Database Debugging and Troubleshooting

This section is to help give some copy-pasta you can use as a reference when you run into some head-banging database problems.

An easy first step is to search for your error in Slack or google “GitLab (my error)”.


Available RAILS_ENV

  • production (generally not for your main GDK db, but you may need this for e.g. omnibus)
  • development (this is your main GDK db)
  • test (used for tests like rspec)

Nuke everything and start over

If you just want to delete everything and start over with an empty DB (~1 minute):

  • bundle exec rake db:reset RAILS_ENV=development

If you just want to delete everything and start over with dummy data (~40 minutes). This also does db:reset and runs DB-specific migrations:

  • bundle exec rake dev:setup RAILS_ENV=development

If your test DB is giving you problems, it is safe to nuke it because it doesn’t contain important data:

  • bundle exec rake db:reset RAILS_ENV=test

Migration wrangling

  • bundle exec rake db:migrate RAILS_ENV=development: Execute any pending migrations that you may have picked up from a MR
  • bundle exec rake db:migrate:status RAILS_ENV=development: Check if all migrations are up or down
  • bundle exec rake db:migrate:down VERSION=20170926203418 RAILS_ENV=development: Tear down a migration
  • bundle exec rake db:migrate:up VERSION=20170926203418 RAILS_ENV=development: Set up a migration
  • bundle exec rake db:migrate:redo VERSION=20170926203418 RAILS_ENV=development: Re-run a specific migration

Manually access the database

Access the database via one of these commands (they all get you to the same place)

gdk psql -d gitlabhq_development
bundle exec rails dbconsole RAILS_ENV=development
bundle exec rails db RAILS_ENV=development
  • \q: Quit/exit
  • \dt: List all tables
  • \d+ issues: List columns for issues table
  • CREATE TABLE board_labels();: Create a table called board_labels
  • SELECT * FROM schema_migrations WHERE version = '20170926203418';: Check if a migration was run
  • DELETE FROM schema_migrations WHERE version = '20170926203418';: Manually remove a migration

FAQ

ActiveRecord::PendingMigrationError with Spring

When running specs with the Spring preloader, the test database can get into a corrupted state. Trying to run the migration or dropping/resetting the test database has no effect.

$ bundle exec spring rspec some_spec.rb
...
Failure/Error: ActiveRecord::Migration.maintain_test_schema!

ActiveRecord::PendingMigrationError:


  Migrations are pending. To resolve this issue, run:

    bin/rake db:migrate RAILS_ENV=test
# ~/.rvm/gems/ruby-2.3.3/gems/activerecord-4.2.10/lib/active_record/migration.rb:392:in `check_pending!'
...
0 examples, 0 failures, 1 error occurred outside of examples

To resolve, you can kill the spring server and app that lives between spec runs.

$ ps aux | grep spring
eric             87304   1.3  2.9  3080836 482596   ??  Ss   10:12AM   4:08.36 spring app    | gitlab | started 6 hours ago | test mode
eric             37709   0.0  0.0  2518640   7524 s006  S    Wed11AM   0:00.79 spring server | gitlab | started 29 hours ago
$ kill 87304
$ kill 37709

db:migrate database version is too old to be migrated error

Users receive this error when db:migrate detects that the current schema version is older than the MIN_SCHEMA_VERSION defined in the Gitlab::Database library module.

Over time we cleanup/combine old migrations in the codebase, so it is not always possible to migrate GitLab from every previous version.

In some cases you may want to bypass this check. For example, if you were on a version of GitLab schema later than the MIN_SCHEMA_VERSION, and then rolled back the to an older migration, from before. In this case, in order to migrate forward again, you should set the SKIP_SCHEMA_VERSION_CHECK environment variable.

bundle exec rake db:migrate SKIP_SCHEMA_VERSION_CHECK=true