Upgrades are usually smooth and restoring from backup is a rare occurrence. However, it's important to know how to recover when problems do arise.
In some cases after a failed upgrade, the fastest solution is to roll back to the previous version you were using.
First, roll back the code or package. For source installations this involves checking out the older version (branch or tag). For Omnibus installations this means installing the older .deb or .rpm package. Then, restore from a backup. Follow the instructions in the Backup and Restore documentation.
When a rollback is necessary it can produce problems on subsequent upgrade attempts. This is because some tables may have been added during the failed upgrade. If these tables are still present after you restore from the older backup it can lead to migration failures on future upgrades.
Starting in GitLab 8.6 we drop all tables prior to importing the backup to prevent this problem. If you've restored a backup to a version prior to 8.6 you may need to manually correct the problem next time you upgrade.
Example error:
== 20151103134857 CreateLfsObjects: migrating =================================
-- create_table(:lfs_objects)
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:
PG::DuplicateTable: ERROR: relation "lfs_objects" already existsCopy the version from the error. In this case the version number is 20151103134857.
WARNING: Use the following steps only if you are certain this is what you need to do.
Pass the version to a database rake task to manually mark the migration as complete.
# Source install
sudo -u git -H bundle exec rake gitlab:db:mark_migration_complete[20151103134857] RAILS_ENV=production
# Omnibus install
sudo gitlab-rake gitlab:db:mark_migration_complete[20151103134857]Once the migration is successfully marked, run the rake db:migrate task again. You will likely have to repeat this process several times until all failed migrations are marked complete.
# Source install
sudo -u git -H bundle exec rails console production
# Omnibus install
sudo gitlab-rails consoleAt the Rails console, type the following commands:
ActiveRecord::Base.connection.execute("INSERT INTO schema_migrations (version) VALUES('20151103134857')")
exitOnce the migration is successfully marked, run the rake db:migrate task again. You will likely have to repeat this process several times until all failed migrations are marked complete.