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Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Account domain blocks (#2381) * Add <ostatus:conversation /> tag to Atom input/output Only uses ref attribute (not href) because href would be the alternate link that's always included also. Creates new conversation for every non-reply status. Carries over conversation for every reply. Keeps remote URIs verbatim, generates local URIs on the fly like the rest of them. * Conversation muting - prevents notifications that reference a conversation (including replies, favourites, reblogs) from being created. API endpoints /api/v1/statuses/:id/mute and /api/v1/statuses/:id/unmute Currently no way to tell when a status/conversation is muted, so the web UI only has a "disable notifications" button, doesn't work as a toggle * Display "Dismiss notifications" on all statuses in notifications column, not just own * Add "muted" as a boolean attribute on statuses JSON For now always false on contained reblogs, since it's only relevant for statuses returned from the notifications endpoint, which are not nested Remove "Disable notifications" from detailed status view, since it's only relevant in the notifications column * Up max class length * Remove pending test for conversation mute * Add tests, clean up * Rename to "mute conversation" and "unmute conversation" * Raise validation error when trying to mute/unmute status without conversation * Adding account domain blocks that filter notifications and public timelines * Add tests for domain blocks in notifications, public timelines Filter reblogs of blocked domains from home * Add API for listing and creating account domain blocks * API for creating/deleting domain blocks, tests for Status#ancestors and Status#descendants, filter domain blocks from them * Filter domains in streaming API * Update account_domain_block_spec.rb
7 years ago
Allow hiding of reblogs from followed users (#5762) * Allow hiding of reblogs from followed users This adds a new entry to the account menu to allow users to hide future reblogs from a user (and then if they've done that, to show future reblogs instead). This does not remove or add historical reblogs from/to the user's timeline; it only affects new statuses. The API for this operates by sending a "reblogs" key to the follow endpoint. If this is sent when starting a new follow, it will be respected from the beginning of the follow relationship (even if the follow request must be approved by the followee). If this is sent when a follow relationship already exists, it will simply update the existing follow relationship. As with the notification muting, this will now return an object ({reblogs: [true|false]}) or false for each follow relationship when requesting relationship information for an account. This should cause few issues due to an object being truthy in many languages, but some modifications may need to be made in pickier languages. Database changes: adds a show_reblogs column (default true, non-nullable) to the follows and follow_requests tables. Because these are non-nullable, we use the existing MigrationHelpers to perform this change without locking those tables, although the tables are likely to be small anyway. Tests included. See also <https://github.com/glitch-soc/mastodon/pull/212>. * Rubocop fixes * Code review changes * Test fixes This patchset closes #648 and resolves #3271. * Rubocop fix * Revert reblogs defaulting in argument, fix tests It turns out we needed this for the same reason we needed it in muting: if nil gets passed in somehow (most usually by an API client not passing any value), we need to detect and handle it. We could specify a default in the parameter and then also catch nil, but there's no great reason to duplicate the default value.
6 years ago
Account domain blocks (#2381) * Add <ostatus:conversation /> tag to Atom input/output Only uses ref attribute (not href) because href would be the alternate link that's always included also. Creates new conversation for every non-reply status. Carries over conversation for every reply. Keeps remote URIs verbatim, generates local URIs on the fly like the rest of them. * Conversation muting - prevents notifications that reference a conversation (including replies, favourites, reblogs) from being created. API endpoints /api/v1/statuses/:id/mute and /api/v1/statuses/:id/unmute Currently no way to tell when a status/conversation is muted, so the web UI only has a "disable notifications" button, doesn't work as a toggle * Display "Dismiss notifications" on all statuses in notifications column, not just own * Add "muted" as a boolean attribute on statuses JSON For now always false on contained reblogs, since it's only relevant for statuses returned from the notifications endpoint, which are not nested Remove "Disable notifications" from detailed status view, since it's only relevant in the notifications column * Up max class length * Remove pending test for conversation mute * Add tests, clean up * Rename to "mute conversation" and "unmute conversation" * Raise validation error when trying to mute/unmute status without conversation * Adding account domain blocks that filter notifications and public timelines * Add tests for domain blocks in notifications, public timelines Filter reblogs of blocked domains from home * Add API for listing and creating account domain blocks * API for creating/deleting domain blocks, tests for Status#ancestors and Status#descendants, filter domain blocks from them * Filter domains in streaming API * Update account_domain_block_spec.rb
7 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
Non-Serial ("Snowflake") IDs (#4801) * Use non-serial IDs This change makes a number of nontrivial tweaks to the data model in Mastodon: * All IDs are now 8 byte integers (rather than mixed 4- and 8-byte) * IDs are now assigned as: * Top 6 bytes: millisecond-resolution time from epoch * Bottom 2 bytes: serial (within the millisecond) sequence number * See /lib/tasks/db.rake's `define_timestamp_id` for details, but note that the purpose of these changes is to make it difficult to determine the number of objects in a table from the ID of any object. * The Redis sorted set used for the feed will have values used to look up toots, rather than scores. This is almost always the same as the existing behavior, except in the case of boosted toots. This change was made because Redis stores scores as double-precision floats, which cannot store the new ID format exactly. Note that this doesn't cause problems with sorting/pagination, because ZREVRANGEBYSCORE sorts lexicographically when scores are tied. (This will still cause sorting issues when the ID gains a new significant digit, but that's extraordinarily uncommon.) Note a couple of tradeoffs have been made in this commit: * lib/tasks/db.rake is used to enforce many/most column constraints, because this commit seems likely to take a while to bring upstream. Enforcing a post-migrate hook is an easier way to maintain the code in the interim. * Boosted toots will appear in the timeline as many times as they have been boosted. This is a tradeoff due to the way the feed is saved in Redis at the moment, but will be handled by a future commit. This would effectively close Mastodon's #1059, as it is a snowflake-like system of generating IDs. However, given how involved the changes were simply within Mastodon, it may have unexpected interactions with some clients, if they store IDs as doubles (or as 4-byte integers). This was a problem that Twitter ran into with their "snowflake" transition, particularly in JavaScript clients that treated IDs as JS integers, rather than strings. It therefore would be useful to test these changes at least in the web interface and popular clients before pushing them to all users. * Fix JavaScript interface with long IDs Somewhat predictably, the JS interface handled IDs as numbers, which in JS are IEEE double-precision floats. This loses some precision when working with numbers as large as those generated by the new ID scheme, so we instead handle them here as strings. This is relatively simple, and doesn't appear to have caused any problems, but should definitely be tested more thoroughly than the built-in tests. Several days of use appear to support this working properly. BREAKING CHANGE: The major(!) change here is that IDs are now returned as strings by the REST endpoints, rather than as integers. In practice, relatively few changes were required to make the existing JS UI work with this change, but it will likely hit API clients pretty hard: it's an entirely different type to consume. (The one API client I tested, Tusky, handles this with no problems, however.) Twitter ran into this issue when introducing Snowflake IDs, and decided to instead introduce an `id_str` field in JSON responses. I have opted to *not* do that, and instead force all IDs to 64-bit integers represented by strings in one go. (I believe Twitter exacerbated their problem by rolling out the changes three times: once for statuses, once for DMs, and once for user IDs, as well as by leaving an integer ID value in JSON. As they said, "If you’re using the `id` field with JSON in a Javascript-related language, there is a very high likelihood that the integers will be silently munged by Javascript interpreters. In most cases, this will result in behavior such as being unable to load or delete a specific direct message, because the ID you're sending to the API is different than the actual identifier associated with the message." [1]) However, given that this is a significant change for API users, alternatives or a transition time may be appropriate. 1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html * Restructure feed pushes/unpushes This was necessary because the previous behavior used Redis zset scores to identify statuses, but those are IEEE double-precision floats, so we can't actually use them to identify all 64-bit IDs. However, it leaves the code in a much better state for refactoring reblog handling / coalescing. Feed-management code has been consolidated in FeedManager, including: * BatchedRemoveStatusService no longer directly manipulates feed zsets * RemoveStatusService no longer directly manipulates feed zsets * PrecomputeFeedService has moved its logic to FeedManager#populate_feed (PrecomputeFeedService largely made lots of calls to FeedManager, but didn't follow the normal adding-to-feed process.) This has the effect of unifying all of the feed push/unpush logic in FeedManager, making it much more tractable to update it in the future. Due to some additional checks that must be made during, for example, batch status removals, some Redis pipelining has been removed. It does not appear that this should cause significantly increased load, but if necessary, some optimizations are possible in batch cases. These were omitted in the pursuit of simplicity, but a batch_push and batch_unpush would be possible in the future. Tests were added to verify that pushes happen under expected conditions, and to verify reblog behavior (both on pushing and unpushing). In the case of unpushing, this includes testing behavior that currently leads to confusion such as Mastodon's #2817, but this codifies that the behavior is currently expected. * Rubocop fixes I could swear I made these changes already, but I must have lost them somewhere along the line. * Address review comments This addresses the first two comments from review of this feature: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735 https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931 This adds an optional argument to FeedManager#key, the subtype of feed key to generate. It also tests to ensure that FeedManager's settings are such that reblogs won't be tracked forever. * Hardcode IdToBigints migration columns This addresses a comment during review: https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452 This means we'll need to make sure that all _id columns going forward are bigints, but that should happen automatically in most cases. * Additional fixes for stringified IDs in JSON These should be the last two. These were identified using eslint to try to identify any plain casts to JavaScript numbers. (Some such casts are legitimate, but these were not.) Adding the following to .eslintrc.yml will identify casts to numbers: ~~~ no-restricted-syntax: - warn - selector: UnaryExpression[operator='+'] > :not(Literal) message: Avoid the use of unary + - selector: CallExpression[callee.name='Number'] message: Casting with Number() may coerce string IDs to numbers ~~~ The remaining three casts appear legitimate: two casts to array indices, one in a server to turn an environment variable into a number. * Only implement timestamp IDs for Status IDs Per discussion in #4801, this is only being merged in for Status IDs at this point. We do this in a migration, as there is no longer use for a post-migration hook. We keep the initialization of the timestamp_id function as a Rake task, as it is also needed after db:schema:load (as db/schema.rb doesn't store Postgres functions). * Change internal streaming payloads to stringified IDs as well This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from #5019, with an extra change for the addition to FeedManager#unpush. * Ensure we have a status_id_seq sequence Apparently this is not a given when specifying a custom ID function, so now we ensure it gets created. This uses the generic version of this function to more easily support adding additional tables with timestamp IDs in the future, although it would be possible to cut this down to a less generic version if necessary. It is only run during db:schema:load or the relevant migration, so the overhead is extraordinarily minimal. * Transition reblogs to new Redis format This provides a one-way migration to transition old Redis reblog entries into the new format, with a separate tracking entry for reblogs. It is not invertible because doing so could (if timestamp IDs are used) require a database query for each status in each users' feed, which is likely to be a significant toll on major instances. * Address review comments from @akihikodaki No functional changes. * Additional review changes * Heredoc cleanup * Run db:schema:load hooks for test in development This matches the behavior in Rails' ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which would otherwise break `rake db:setup` in development. It also moves some functionality out to a library, which will be a good place to put additional related functionality in the near future.
6 years ago
  1. require 'rails_helper'
  2. RSpec.describe FeedManager do
  3. before do |example|
  4. unless example.metadata[:skip_stub]
  5. stub_const 'FeedManager::MAX_ITEMS', 10
  6. stub_const 'FeedManager::REBLOG_FALLOFF', 4
  7. end
  8. end
  9. it 'tracks at least as many statuses as reblogs', skip_stub: true do
  10. expect(FeedManager::REBLOG_FALLOFF).to be <= FeedManager::MAX_ITEMS
  11. end
  12. describe '#key' do
  13. subject { FeedManager.instance.key(:home, 1) }
  14. it 'returns a string' do
  15. expect(subject).to be_a String
  16. end
  17. end
  18. describe '#filter?' do
  19. let(:alice) { Fabricate(:account, username: 'alice') }
  20. let(:bob) { Fabricate(:account, username: 'bob', domain: 'example.com') }
  21. let(:jeff) { Fabricate(:account, username: 'jeff') }
  22. context 'for home feed' do
  23. it 'returns false for followee\'s status' do
  24. status = Fabricate(:status, text: 'Hello world', account: alice)
  25. bob.follow!(alice)
  26. expect(FeedManager.instance.filter?(:home, status, bob.id)).to be false
  27. end
  28. it 'returns false for reblog by followee' do
  29. status = Fabricate(:status, text: 'Hello world', account: jeff)
  30. reblog = Fabricate(:status, reblog: status, account: alice)
  31. bob.follow!(alice)
  32. expect(FeedManager.instance.filter?(:home, reblog, bob.id)).to be false
  33. end
  34. it 'returns true for reblog by followee of blocked account' do
  35. status = Fabricate(:status, text: 'Hello world', account: jeff)
  36. reblog = Fabricate(:status, reblog: status, account: alice)
  37. bob.follow!(alice)
  38. bob.block!(jeff)
  39. expect(FeedManager.instance.filter?(:home, reblog, bob.id)).to be true
  40. end
  41. it 'returns true for reblog by followee of muted account' do
  42. status = Fabricate(:status, text: 'Hello world', account: jeff)
  43. reblog = Fabricate(:status, reblog: status, account: alice)
  44. bob.follow!(alice)
  45. bob.mute!(jeff)
  46. expect(FeedManager.instance.filter?(:home, reblog, bob.id)).to be true
  47. end
  48. it 'returns true for reblog by followee of someone who is blocking recipient' do
  49. status = Fabricate(:status, text: 'Hello world', account: jeff)
  50. reblog = Fabricate(:status, reblog: status, account: alice)
  51. bob.follow!(alice)
  52. jeff.block!(bob)
  53. expect(FeedManager.instance.filter?(:home, reblog, bob.id)).to be true
  54. end
  55. it 'returns true for reblog from account with reblogs disabled' do
  56. status = Fabricate(:status, text: 'Hello world', account: jeff)
  57. reblog = Fabricate(:status, reblog: status, account: alice)
  58. bob.follow!(alice, reblogs: false)
  59. expect(FeedManager.instance.filter?(:home, reblog, bob.id)).to be true
  60. end
  61. it 'returns false for reply by followee to another followee' do
  62. status = Fabricate(:status, text: 'Hello world', account: jeff)
  63. reply = Fabricate(:status, text: 'Nay', thread: status, account: alice)
  64. bob.follow!(alice)
  65. bob.follow!(jeff)
  66. expect(FeedManager.instance.filter?(:home, reply, bob.id)).to be false
  67. end
  68. it 'returns false for reply by followee to recipient' do
  69. status = Fabricate(:status, text: 'Hello world', account: bob)
  70. reply = Fabricate(:status, text: 'Nay', thread: status, account: alice)
  71. bob.follow!(alice)
  72. expect(FeedManager.instance.filter?(:home, reply, bob.id)).to be false
  73. end
  74. it 'returns false for reply by followee to self' do
  75. status = Fabricate(:status, text: 'Hello world', account: alice)
  76. reply = Fabricate(:status, text: 'Nay', thread: status, account: alice)
  77. bob.follow!(alice)
  78. expect(FeedManager.instance.filter?(:home, reply, bob.id)).to be false
  79. end
  80. it 'returns true for reply by followee to non-followed account' do
  81. status = Fabricate(:status, text: 'Hello world', account: jeff)
  82. reply = Fabricate(:status, text: 'Nay', thread: status, account: alice)
  83. bob.follow!(alice)
  84. expect(FeedManager.instance.filter?(:home, reply, bob.id)).to be true
  85. end
  86. it 'returns true for the second reply by followee to a non-federated status' do
  87. reply = Fabricate(:status, text: 'Reply 1', reply: true, account: alice)
  88. second_reply = Fabricate(:status, text: 'Reply 2', thread: reply, account: alice)
  89. bob.follow!(alice)
  90. expect(FeedManager.instance.filter?(:home, second_reply, bob.id)).to be true
  91. end
  92. it 'returns false for status by followee mentioning another account' do
  93. bob.follow!(alice)
  94. status = PostStatusService.new.call(alice, text: 'Hey @jeff')
  95. expect(FeedManager.instance.filter?(:home, status, bob.id)).to be false
  96. end
  97. it 'returns true for status by followee mentioning blocked account' do
  98. bob.block!(jeff)
  99. bob.follow!(alice)
  100. status = PostStatusService.new.call(alice, text: 'Hey @jeff')
  101. expect(FeedManager.instance.filter?(:home, status, bob.id)).to be true
  102. end
  103. it 'returns true for reblog of a personally blocked domain' do
  104. alice.block_domain!('example.com')
  105. alice.follow!(jeff)
  106. status = Fabricate(:status, text: 'Hello world', account: bob)
  107. reblog = Fabricate(:status, reblog: status, account: jeff)
  108. expect(FeedManager.instance.filter?(:home, reblog, alice.id)).to be true
  109. end
  110. context 'for irreversibly muted phrases' do
  111. it 'considers word boundaries when matching' do
  112. alice.custom_filters.create!(phrase: 'bob', context: %w(home), irreversible: true)
  113. alice.follow!(jeff)
  114. status = Fabricate(:status, text: 'bobcats', account: jeff)
  115. expect(FeedManager.instance.filter?(:home, status, alice.id)).to be_falsy
  116. end
  117. it 'returns true if phrase is contained' do
  118. alice.custom_filters.create!(phrase: 'farts', context: %w(home public), irreversible: true)
  119. alice.custom_filters.create!(phrase: 'pop tarts', context: %w(home), irreversible: true)
  120. alice.follow!(jeff)
  121. status = Fabricate(:status, text: 'i sure like POP TARts', account: jeff)
  122. expect(FeedManager.instance.filter?(:home, status, alice.id)).to be true
  123. end
  124. it 'matches substrings if whole_word is false' do
  125. alice.custom_filters.create!(phrase: 'take', context: %w(home), whole_word: false, irreversible: true)
  126. alice.follow!(jeff)
  127. status = Fabricate(:status, text: 'shiitake', account: jeff)
  128. expect(FeedManager.instance.filter?(:home, status, alice.id)).to be true
  129. end
  130. it 'returns true if phrase is contained in a poll option' do
  131. alice.custom_filters.create!(phrase: 'farts', context: %w(home public), irreversible: true)
  132. alice.custom_filters.create!(phrase: 'pop tarts', context: %w(home), irreversible: true)
  133. alice.follow!(jeff)
  134. status = Fabricate(:status, text: 'what do you prefer', poll: Fabricate(:poll, options: %w(farts POP TARts)), account: jeff)
  135. expect(FeedManager.instance.filter?(:home, status, alice.id)).to be true
  136. end
  137. end
  138. end
  139. context 'for mentions feed' do
  140. it 'returns true for status that mentions blocked account' do
  141. bob.block!(jeff)
  142. status = PostStatusService.new.call(alice, text: 'Hey @jeff')
  143. expect(FeedManager.instance.filter?(:mentions, status, bob.id)).to be true
  144. end
  145. it 'returns true for status that replies to a blocked account' do
  146. status = Fabricate(:status, text: 'Hello world', account: jeff)
  147. reply = Fabricate(:status, text: 'Nay', thread: status, account: alice)
  148. bob.block!(jeff)
  149. expect(FeedManager.instance.filter?(:mentions, reply, bob.id)).to be true
  150. end
  151. it 'returns true for status by silenced account who recipient is not following' do
  152. status = Fabricate(:status, text: 'Hello world', account: alice)
  153. alice.silence!
  154. expect(FeedManager.instance.filter?(:mentions, status, bob.id)).to be true
  155. end
  156. it 'returns false for status by followed silenced account' do
  157. status = Fabricate(:status, text: 'Hello world', account: alice)
  158. alice.silence!
  159. bob.follow!(alice)
  160. expect(FeedManager.instance.filter?(:mentions, status, bob.id)).to be false
  161. end
  162. end
  163. end
  164. describe '#push_to_home' do
  165. it 'trims timelines if they will have more than FeedManager::MAX_ITEMS' do
  166. account = Fabricate(:account)
  167. status = Fabricate(:status)
  168. members = FeedManager::MAX_ITEMS.times.map { |count| [count, count] }
  169. Redis.current.zadd("feed:home:#{account.id}", members)
  170. FeedManager.instance.push_to_home(account, status)
  171. expect(Redis.current.zcard("feed:home:#{account.id}")).to eq FeedManager::MAX_ITEMS
  172. end
  173. context 'reblogs' do
  174. it 'saves reblogs of unseen statuses' do
  175. account = Fabricate(:account)
  176. reblogged = Fabricate(:status)
  177. reblog = Fabricate(:status, reblog: reblogged)
  178. expect(FeedManager.instance.push_to_home(account, reblog)).to be true
  179. end
  180. it 'does not save a new reblog of a recent status' do
  181. account = Fabricate(:account)
  182. reblogged = Fabricate(:status)
  183. reblog = Fabricate(:status, reblog: reblogged)
  184. FeedManager.instance.push_to_home(account, reblogged)
  185. expect(FeedManager.instance.push_to_home(account, reblog)).to be false
  186. end
  187. it 'saves a new reblog of an old status' do
  188. account = Fabricate(:account)
  189. reblogged = Fabricate(:status)
  190. reblog = Fabricate(:status, reblog: reblogged)
  191. FeedManager.instance.push_to_home(account, reblogged)
  192. # Fill the feed with intervening statuses
  193. FeedManager::REBLOG_FALLOFF.times do
  194. FeedManager.instance.push_to_home(account, Fabricate(:status))
  195. end
  196. expect(FeedManager.instance.push_to_home(account, reblog)).to be true
  197. end
  198. it 'does not save a new reblog of a recently-reblogged status' do
  199. account = Fabricate(:account)
  200. reblogged = Fabricate(:status)
  201. reblogs = 2.times.map { Fabricate(:status, reblog: reblogged) }
  202. # The first reblog will be accepted
  203. FeedManager.instance.push_to_home(account, reblogs.first)
  204. # The second reblog should be ignored
  205. expect(FeedManager.instance.push_to_home(account, reblogs.last)).to be false
  206. end
  207. it 'saves a new reblog of a recently-reblogged status when previous reblog has been deleted' do
  208. account = Fabricate(:account)
  209. reblogged = Fabricate(:status)
  210. old_reblog = Fabricate(:status, reblog: reblogged)
  211. # The first reblog should be accepted
  212. expect(FeedManager.instance.push_to_home(account, old_reblog)).to be true
  213. # The first reblog should be successfully removed
  214. expect(FeedManager.instance.unpush_from_home(account, old_reblog)).to be true
  215. reblog = Fabricate(:status, reblog: reblogged)
  216. # The second reblog should be accepted
  217. expect(FeedManager.instance.push_to_home(account, reblog)).to be true
  218. end
  219. it 'does not save a new reblog of a multiply-reblogged-then-unreblogged status' do
  220. account = Fabricate(:account)
  221. reblogged = Fabricate(:status)
  222. reblogs = 3.times.map { Fabricate(:status, reblog: reblogged) }
  223. # Accept the reblogs
  224. FeedManager.instance.push_to_home(account, reblogs[0])
  225. FeedManager.instance.push_to_home(account, reblogs[1])
  226. # Unreblog the first one
  227. FeedManager.instance.unpush_from_home(account, reblogs[0])
  228. # The last reblog should still be ignored
  229. expect(FeedManager.instance.push_to_home(account, reblogs.last)).to be false
  230. end
  231. it 'saves a new reblog of a long-ago-reblogged status' do
  232. account = Fabricate(:account)
  233. reblogged = Fabricate(:status)
  234. reblogs = 2.times.map { Fabricate(:status, reblog: reblogged) }
  235. # The first reblog will be accepted
  236. FeedManager.instance.push_to_home(account, reblogs.first)
  237. # Fill the feed with intervening statuses
  238. FeedManager::REBLOG_FALLOFF.times do
  239. FeedManager.instance.push_to_home(account, Fabricate(:status))
  240. end
  241. # The second reblog should also be accepted
  242. expect(FeedManager.instance.push_to_home(account, reblogs.last)).to be true
  243. end
  244. end
  245. it "does not push when the given status's reblog is already inserted" do
  246. account = Fabricate(:account)
  247. reblog = Fabricate(:status)
  248. status = Fabricate(:status, reblog: reblog)
  249. FeedManager.instance.push_to_home(account, status)
  250. expect(FeedManager.instance.push_to_home(account, reblog)).to eq false
  251. end
  252. end
  253. describe '#push_to_list' do
  254. it "does not push when the given status's reblog is already inserted" do
  255. list = Fabricate(:list)
  256. reblog = Fabricate(:status)
  257. status = Fabricate(:status, reblog: reblog)
  258. FeedManager.instance.push_to_list(list, status)
  259. expect(FeedManager.instance.push_to_list(list, reblog)).to eq false
  260. end
  261. end
  262. describe '#merge_into_timeline' do
  263. it "does not push source account's statuses whose reblogs are already inserted" do
  264. account = Fabricate(:account, id: 0)
  265. reblog = Fabricate(:status)
  266. status = Fabricate(:status, reblog: reblog)
  267. FeedManager.instance.push_to_home(account, status)
  268. FeedManager.instance.merge_into_timeline(account, reblog.account)
  269. expect(Redis.current.zscore("feed:home:0", reblog.id)).to eq nil
  270. end
  271. end
  272. describe '#trim' do
  273. let(:receiver) { Fabricate(:account) }
  274. it 'cleans up reblog tracking keys' do
  275. reblogged = Fabricate(:status)
  276. status = Fabricate(:status, reblog: reblogged)
  277. another_status = Fabricate(:status, reblog: reblogged)
  278. reblogs_key = FeedManager.instance.key('home', receiver.id, 'reblogs')
  279. reblog_set_key = FeedManager.instance.key('home', receiver.id, "reblogs:#{reblogged.id}")
  280. FeedManager.instance.push_to_home(receiver, status)
  281. FeedManager.instance.push_to_home(receiver, another_status)
  282. # We should have a tracking set and an entry in reblogs.
  283. expect(Redis.current.exists(reblog_set_key)).to be true
  284. expect(Redis.current.zrange(reblogs_key, 0, -1)).to eq [reblogged.id.to_s]
  285. # Push everything off the end of the feed.
  286. FeedManager::MAX_ITEMS.times do
  287. FeedManager.instance.push_to_home(receiver, Fabricate(:status))
  288. end
  289. # `trim` should be called automatically, but do it anyway, as
  290. # we're testing `trim`, not side effects of `push`.
  291. FeedManager.instance.trim('home', receiver.id)
  292. # We should not have any reblog tracking data.
  293. expect(Redis.current.exists(reblog_set_key)).to be false
  294. expect(Redis.current.zrange(reblogs_key, 0, -1)).to be_empty
  295. end
  296. end
  297. describe '#unpush' do
  298. let(:receiver) { Fabricate(:account) }
  299. it 'leaves a reblogged status if original was on feed' do
  300. reblogged = Fabricate(:status)
  301. status = Fabricate(:status, reblog: reblogged)
  302. FeedManager.instance.push_to_home(receiver, reblogged)
  303. FeedManager::REBLOG_FALLOFF.times { FeedManager.instance.push_to_home(receiver, Fabricate(:status)) }
  304. FeedManager.instance.push_to_home(receiver, status)
  305. # The reblogging status should show up under normal conditions.
  306. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to include(status.id.to_s)
  307. FeedManager.instance.unpush_from_home(receiver, status)
  308. # Restore original status
  309. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to_not include(status.id.to_s)
  310. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to include(reblogged.id.to_s)
  311. end
  312. it 'removes a reblogged status if it was only reblogged once' do
  313. reblogged = Fabricate(:status)
  314. status = Fabricate(:status, reblog: reblogged)
  315. FeedManager.instance.push_to_home(receiver, status)
  316. # The reblogging status should show up under normal conditions.
  317. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to eq [status.id.to_s]
  318. FeedManager.instance.unpush_from_home(receiver, status)
  319. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to be_empty
  320. end
  321. it 'leaves a multiply-reblogged status if another reblog was in feed' do
  322. reblogged = Fabricate(:status)
  323. reblogs = 3.times.map { Fabricate(:status, reblog: reblogged) }
  324. reblogs.each do |reblog|
  325. FeedManager.instance.push_to_home(receiver, reblog)
  326. end
  327. # The reblogging status should show up under normal conditions.
  328. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to eq [reblogs.first.id.to_s]
  329. reblogs[0...-1].each do |reblog|
  330. FeedManager.instance.unpush_from_home(receiver, reblog)
  331. end
  332. expect(Redis.current.zrange("feed:home:#{receiver.id}", 0, -1)).to eq [reblogs.last.id.to_s]
  333. end
  334. it 'sends push updates' do
  335. status = Fabricate(:status)
  336. FeedManager.instance.push_to_home(receiver, status)
  337. allow(Redis.current).to receive_messages(publish: nil)
  338. FeedManager.instance.unpush_from_home(receiver, status)
  339. deletion = Oj.dump(event: :delete, payload: status.id.to_s)
  340. expect(Redis.current).to have_received(:publish).with("timeline:#{receiver.id}", deletion)
  341. end
  342. end
  343. describe '#clear_from_timeline' do
  344. let(:account) { Fabricate(:account) }
  345. let(:followed_account) { Fabricate(:account) }
  346. let(:target_account) { Fabricate(:account) }
  347. let(:status_1) { Fabricate(:status, account: followed_account) }
  348. let(:status_2) { Fabricate(:status, account: target_account) }
  349. let(:status_3) { Fabricate(:status, account: followed_account, mentions: [Fabricate(:mention, account: target_account)]) }
  350. let(:status_4) { Fabricate(:status, mentions: [Fabricate(:mention, account: target_account)]) }
  351. let(:status_5) { Fabricate(:status, account: followed_account, reblog: status_4) }
  352. let(:status_6) { Fabricate(:status, account: followed_account, reblog: status_2) }
  353. let(:status_7) { Fabricate(:status, account: followed_account) }
  354. before do
  355. [status_1, status_3, status_5, status_6, status_7].each do |status|
  356. Redis.current.zadd("feed:home:#{account.id}", status.id, status.id)
  357. end
  358. end
  359. it 'correctly cleans the timeline' do
  360. FeedManager.instance.clear_from_timeline(account, target_account)
  361. expect(Redis.current.zrange("feed:home:#{account.id}", 0, -1)).to eq [status_1.id.to_s, status_7.id.to_s]
  362. end
  363. end
  364. end