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 ".


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