====== performance ======

  * sidekiq: by default there is 1 process and X threads
    * increase number of workers
    * note: RSS usage is ~1GB per process
  * CI:
    * enable long pooling if instance has many runner
  * [[https://docs.gitlab.com/administration/operations/fast_ssh_key_lookup/|Fast lookup of SSH keys]]
  * [[https://docs.gitlab.com/topics/git/troubleshooting_git/#increase-the-number-of-unauthenticated-concurrent-ssh-connections|Increase the number of unauthenticated concurrent SSH connections]]