GitLab Documentation

Sidekiq MemoryKiller

The GitLab Rails application code suffers from memory leaks. For web requests this problem is made manageable using unicorn-worker-killer which restarts Unicorn worker processes in between requests when needed. The Sidekiq MemoryKiller applies the same approach to the Sidekiq processes used by GitLab to process background jobs.

Unlike unicorn-worker-killer, which is enabled by default for all GitLab installations since GitLab 6.4, the Sidekiq MemoryKiller is enabled by default only for Omnibus packages. The reason for this is that the MemoryKiller relies on Runit to restart Sidekiq after a memory-induced shutdown and GitLab installations from source do not all use Runit or an equivalent.

With the default settings, the MemoryKiller will cause a Sidekiq restart no more often than once every 15 minutes, with the restart causing about one minute of delay for incoming background jobs.

Configuring the MemoryKiller

The MemoryKiller is controlled using environment variables.