Tweaks for GitLab

Reduce memory usage on small instances

Run puma in single process mode

By default, ?puma is run in cluster mode, with three dedicated workers. According to some measurements you can reclaim up to 250MB of memory by disabling this cluster mode in favour of a single process.

Disabling puma cluster mode is done in the configuration file /etc/gitlab/puma.rb. Look for the following line:

workers 3

and replace it with:

workers 0

Once the change in configuration is done, you need to restart puma with:

# service gitlab-puma.service restart