mastodon/db/migrate
aschmitz 97c02c3389 Make IdsToBigints (mostly!) non-blocking (#5088)
* Make IdsToBigints (mostly!) non-blocking

This pulls in GitLab's MigrationHelpers, which include code to make
column changes in ways that Postgres can do without locking. In general,
this involves creating a new column, adding an index and any foreign
keys as appropriate, adding a trigger to keep it populated alongside
the old column, and then progressively copying data over to the new
column, before removing the old column and replacing it with the new
one.

A few changes to GitLab's MigrationHelpers were necessary:

* Some changes were made to remove dependencies on other GitLab code.
* We explicitly wait for index creation before forging ahead on column
  replacements.
* We use different temporary column names, to avoid running into index
  name length limits.
* We rename the generated indices back to what they "should" be after
  replacing columns.
* We rename the generated foreign keys to use the new column names when
  we had to create them. (This allows the migration to be rolled back
  without incident.)

# Big Scary Warning

There are two things here that may trip up large instances:

1. The change for tables' "id" columns is not concurrent. In
   particular, the stream_entries table may be big, and does not
   concurrently migrate its id column. (On the other hand, x_id type
   columns are all concurrent.)
2. This migration will take a long time to run, *but it should not
   lock tables during that time* (with the exception of the "id"
   columns as described above). That means this should probably be run
   in `screen` or some other session that can be run for a long time.
   Notably, the migration will take *longer* than it would without
   these changes, but the website will still be responsive during that
   time.

These changes were tested on a relatively large statuses table (256k
entries), and the service remained responsive during the migration.
Migrations both forward and backward were tested.

* Rubocop fixes

* MigrationHelpers: Support ID columns in some cases

This doesn't work in cases where the ID column is referred to as a
foreign key by another table.

* MigrationHelpers: support foreign keys for ID cols

Note that this does not yet support foreign keys on non-primary-key
columns, but Mastodon also doesn't yet have any that we've needed to
migrate.

This means we can perform fully "concurrent" migrations to change ID
column types, and the IdsToBigints migration can happen with effectively
no downtime. (A few operations require a transaction, such as renaming
columns or deleting them, but these transactions should not block for
noticeable amounts of time.)

The algorithm for generating foreign key names has changed with this,
and therefore all of those changed in schema.rb.

* Provide status, allow for interruptions

The MigrationHelpers now allow restarting the rename of a column if it
was interrupted, by removing the old "new column" and re-starting the
process.

Along with this, they now provide status updates on the changes which
are happening, as well as indications about when the changes can be
safely interrupted (when there are at least 10 seconds estimated to be
left before copying data is complete).

The IdsToBigints migration now also sorts the columns it migrates by
size, starting with the largest tables. This should provide
administrators a worst-case scenario estimate for the length of
migrations: each successive change will get faster, giving admins a
chance to abort early on if they need to run the migration later. The
idea is that this does not force them to try to time interruptions
between smaller migrations.

* Fix column sorting in IdsToBigints

Not a significant change, but it impacts the order of columns in the
database and db/schema.rb.

* Actually pause before IdsToBigints
2017-10-02 21:28:59 +02:00
..
20160220174730_create_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160220211917_create_statuses.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160221003140_create_users.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160221003621_create_follows.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160222122600_create_stream_entries.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160222143943_add_profile_fields_to_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160223162837_add_metadata_to_statuses.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160223164502_make_uris_nullable_in_statuses.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160223165723_add_url_to_statuses.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160223165855_add_url_to_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160223171800_create_favourites.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160224223247_create_mentions.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160227230233_add_attachment_avatar_to_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160305115639_add_devise_to_users.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160306172223_create_doorkeeper_tables.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160312193225_add_attachment_header_to_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160314164231_add_owner_to_application.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160316103650_add_missing_indices.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160322193748_add_avatar_remote_url_to_accounts.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160325130944_add_admin_to_users.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20160826155805_add_superapp_to_oauth_applications.rb
20160905150353_create_media_attachments.rb
20160919221059_add_subscription_expires_at_to_accounts.rb
20160920003904_remove_verify_token_from_accounts.rb
20160926213048_remove_owner_from_application.rb
20161003142332_add_confirmable_to_users.rb
20161003145426_create_blocks.rb
20161006213403_rails_settings_migration.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20161009120834_create_domain_blocks.rb
20161027172456_add_silenced_to_accounts.rb
20161104173623_create_tags.rb
20161105130633_create_statuses_tags_join_table.rb
20161116162355_add_locale_to_users.rb
20161119211120_create_notifications.rb
20161122163057_remove_unneeded_indexes.rb
20161123093447_add_sensitive_to_statuses.rb
20161128103007_create_subscriptions.rb
20161130142058_add_last_successful_delivery_at_to_subscriptions.rb
20161130185319_add_visibility_to_statuses.rb
20161202132159_add_in_reply_to_account_id_to_statuses.rb
20161203164520_add_from_account_id_to_notifications.rb
20161205214545_add_suspended_to_accounts.rb
20161221152630_add_hidden_to_stream_entries.rb
20161222201034_add_locked_to_accounts.rb
20161222204147_create_follow_requests.rb
20170105224407_add_shortcode_to_media_attachments.rb
20170109120109_create_web_settings.rb Persist UI settings, add missing localizations for German 2017-01-09 14:00:55 +01:00
20170112154826_migrate_settings.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20170114194937_add_application_to_statuses.rb Add tracking of OAuth app that posted a status, extend OAuth apps to have optional website field, add application details to API, show application name and website on detailed status views. Resolves #11 2017-01-15 08:58:50 +11:00
20170114203041_add_website_to_oauth_application.rb Add tracking of OAuth app that posted a status, extend OAuth apps to have optional website field, add application details to API, show application name and website on detailed status views. Resolves #11 2017-01-15 08:58:50 +11:00
20170119214911_create_preview_cards.rb Fix #463 - Fetch and display previews of URLs using OpenGraph tags 2017-01-20 01:00:14 +01:00
20170123162658_add_severity_to_domain_blocks.rb Domain blocks now have varying severity - auto-suspend vs auto-silence 2017-01-23 17:38:38 +01:00
20170123203248_add_reject_media_to_domain_blocks.rb Optional domain block attribute that prevents media attachments from being downloaded 2017-01-23 21:36:08 +01:00
20170125145934_add_spoiler_text_to_statuses.rb Fix spoiler_text not having "not null" constraint 2017-01-25 15:24:19 +01:00
20170127165745_add_devise_two_factor_to_users.rb Added optional two-factor authentication 2017-01-27 20:35:16 +01:00
20170129000348_create_devices.rb API for apps to register for push notifications 2017-01-29 01:30:32 +01:00
20170205175257_remove_devices.rb Fix #61 - Add list of blocked users to the UI; clean up failed push notifications API 2017-02-05 19:18:11 +01:00
20170209184350_add_reply_to_statuses.rb Fix #614 - extra reply-boolean on statuses to account for cases when replied-to 2017-02-09 20:25:39 +01:00
20170214110202_create_reports.rb Adding POST /api/v1/reports API, and a UI for submitting reports 2017-02-14 20:59:26 +01:00
20170217012631_add_reblog_of_id_foreign_key_to_statuses.rb Add foreign key to prevent reblogs of non-existent (after race conditions) statuses from happening 2017-02-17 02:33:10 +01:00
20170301222600_create_mutes.rb Feature conversations muting (#3017) 2017-05-15 03:04:13 +02:00
20170303212857_add_last_emailed_at_to_users.rb Add digest e-mails 2017-03-04 00:00:48 +01:00
20170304202101_add_type_to_media_attachments.rb Fix #431 - convert gif to webm during upload. Web UI treats them like it did 2017-03-04 23:02:24 +01:00
20170317193015_add_search_index_to_accounts.rb Make account search blazing fast and rank followers/followees higher in the results 2017-03-17 20:48:14 +01:00
20170318214217_add_header_remote_url_to_accounts.rb Federate header images, fix open-uri http->https redirection error 2017-03-18 22:51:20 +01:00
20170322021028_add_lowercase_index_to_accounts.rb More efficient single account retrieval (0.9ms vs 50ms before) 2017-03-22 03:21:38 +01:00
20170322143850_change_primary_key_to_bigint_on_statuses.rb Upgrade status IDs to bigint 2017-03-22 15:46:58 +01:00
20170322162804_add_search_index_to_tags.rb Fix full-text search query quotation, improve tag search performance with an index, 2017-03-22 17:36:34 +01:00
20170330021336_add_counter_caches.rb Fix up null values on latest migration, add notes 2017-03-30 16:06:27 +02:00
20170330163835_create_imports.rb Import feature for following/blocking lists (addresses #62, #177, #201, #454) 2017-03-30 19:42:33 +02:00
20170330164118_add_attachment_data_to_imports.rb Add migration versions (#3574) 2017-06-05 02:43:02 +02:00
20170403172249_add_action_taken_by_account_id_to_reports.rb Add basic logging of who resolved report 2017-04-03 19:35:00 +02:00
20170405112956_add_index_on_mentions_status_id.rb Add index on mentions status_id 2017-04-05 13:32:57 +02:00
20170406215816_add_notifications_and_favourites_indices.rb Low-hanging fruit of query optimization, these indices were missing 2017-04-07 00:04:38 +02:00
20170409170753_add_last_webfingered_at_to_accounts.rb Refresh webfinger (#1323) 2017-04-15 03:16:05 +02:00
20170414080609_add_devise_two_factor_backupable_to_users.rb Add recovery code support for two-factor auth (#1773) 2017-04-15 13:26:03 +02:00
20170414132105_add_language_to_statuses.rb Add language detection (#1772) 2017-04-16 20:32:17 +02:00
20170418160728_add_indexes_to_reports_for_accounts.rb Admin reports with accounts (#2092) 2017-04-18 19:36:18 +02:00
20170423005413_add_allowed_languages_to_user.rb Filter on allowed user language preferences (#2361) 2017-05-01 17:42:13 +02:00
20170424003227_create_account_domain_blocks.rb Account domain blocks (#2381) 2017-05-19 01:14:30 +02:00
20170424112722_add_status_id_index_to_statuses_tags.rb Add index to statuses_tags#status_id (#2394) 2017-04-24 15:10:14 +02:00
20170425131920_add_media_attachment_meta.rb Add media dimensions (#2448) 2017-04-26 03:48:12 +02:00
20170425202925_add_oembed_to_preview_cards.rb OEmbed support for PreviewCard (#2337) 2017-04-27 14:42:22 +02:00
20170427011934_re_add_owner_to_application.rb Application prefs section (#2758) 2017-08-22 18:33:57 +02:00
20170506235850_create_conversations.rb Add conversation model, <ostatus:conversation /> (#3016) 2017-05-12 19:09:21 +02:00
20170507000211_add_conversation_id_to_statuses.rb Add conversation model, <ostatus:conversation /> (#3016) 2017-05-12 19:09:21 +02:00
20170507141759_optimize_index_subscriptions.rb Add effective index to subscriptions (#2885) 2017-05-07 19:00:20 +02:00
20170508230434_create_conversation_mutes.rb Feature conversations muting (#3017) 2017-05-15 03:04:13 +02:00
20170516072309_add_index_accounts_on_uri.rb Make faster ProcessFeedService (#3080) 2017-05-16 12:12:29 +02:00
20170520145338_change_language_filter_to_opt_out.rb Filter languages with opt out (#3175) 2017-05-20 17:32:44 +02:00
20170601210557_add_index_on_media_attachments_account_id.rb Add index to media_attachments.account_id (#3510) 2017-06-02 16:18:54 +02:00
20170604144747_add_foreign_keys_for_accounts.rb Fix #3550 - Add all missing foreign keys (#3562) 2017-06-05 13:24:00 +02:00
20170606113804_change_tag_search_index_to_btree.rb Fix tag search order and not to use tsvector (#3611) 2017-06-06 16:07:06 +02:00
20170609145826_remove_default_language_from_statuses.rb Language detection defaults to nil (#3666) 2017-06-09 18:09:37 +02:00
20170610000000_add_statuses_index_on_account_id_id.rb Add index statuses on account_id and id (#3895) 2017-06-23 17:46:00 +02:00
20170623152212_create_session_activations.rb Revocable sessions (#3616) 2017-06-23 18:50:53 +02:00
20170624134742_add_description_to_session_activations.rb Add overview of active sessions (#3929) 2017-06-25 16:54:30 +02:00
20170625140443_add_access_token_id_to_session_activations.rb Bind web UI access tokens to sessions (#3940) 2017-06-25 23:51:32 +02:00
20170711225116_fix_null_booleans.rb Fix boolean columns sometimes having a null value (#4162) 2017-07-13 03:12:25 +02:00
20170713112503_make_tag_search_case_insensitive.rb Make tag search case insensitive again (#4184) 2017-07-13 19:31:33 +02:00
20170713175513_create_web_push_subscriptions.rb Web Push Notifications (#3243) 2017-07-13 22:15:32 +02:00
20170713190709_add_web_push_subscription_to_session_activations.rb Web Push Notifications (#3243) 2017-07-13 22:15:32 +02:00
20170714184731_add_domain_to_subscriptions.rb Fix #2672 - Connect signed PuSH subscription requests to instance domain (#4205) 2017-07-14 23:01:20 +02:00
20170718211102_add_activitypub_to_accounts.rb Add ActivityPub attributes to accounts (#4273) 2017-07-19 17:06:46 +02:00
20170720000000_add_index_favourites_on_account_id_and_id.rb Add index favourites on account_id and id (#4360) 2017-07-26 03:35:25 +02:00
20170823162448_create_status_pins.rb Pinned statuses (#4675) 2017-08-25 01:41:18 +02:00
20170824103029_add_timestamps_to_status_pins.rb Allow multiple pinned statuses to be shown and make them be ordered b… (#4690) 2017-08-25 18:50:52 +02:00
20170829215220_remove_status_pins_account_index.rb Remove unneccesary indices (#4738) 2017-08-30 05:04:20 +02:00
20170901141119_truncate_preview_cards.rb Make PreviewCard records reuseable between statuses (#4642) 2017-09-01 16:20:16 +02:00
20170901142658_create_join_table_preview_cards_statuses.rb Make PreviewCard records reuseable between statuses (#4642) 2017-09-01 16:20:16 +02:00
20170905044538_add_index_id_account_id_activity_type_on_notifications.rb add index_notifications_on_id_and_account_id_and_activity_type on notifications table (#4750) 2017-09-05 12:30:01 +02:00
20170905165803_add_local_to_statuses.rb Fix locking migration on statuses table. Nullable column and NO default value (#4825) 2017-09-06 20:57:52 +02:00
20170913000752_create_site_uploads.rb Uploads for admin site settings (#4913) 2017-09-14 00:04:30 +02:00
20170917153509_create_custom_emojis.rb Custom emoji (#4988) 2017-09-19 02:42:40 +02:00
20170918125918_ids_to_bigints.rb Make IdsToBigints (mostly!) non-blocking (#5088) 2017-10-02 21:28:59 +02:00
20170924022025_ids_to_bigints2.rb Forgotten in #5039, change statuses_tags tag_id to bigint (#5070) 2017-09-24 05:58:07 +02:00
20170927215609_add_description_to_media_attachments.rb Add ability to specify alternative text for media attachments (#5123) 2017-09-28 15:31:31 +02:00