Document how and when to run Puma in Single mode, limitations
- We need to document how to run Puma in Single mode
- We need to tell when it's relevant (for memory contained env)
- We need to explain the limitations (and link the issues from this epic)
A wider issue on running in limited env Documentation: #289909 (closed)
How to start Puma in Single mode
- In
/etc/gitlab/gitlab.rb
, setpuma['worker_processes'] = 0
(see https://github.com/puma/puma/blob/5af91ff6aa14ab373184ad908d5ff5ac637eda4a/lib/puma/launcher.rb#L367) - Set
PUMA_SKIP_CLUSTER_VALIDATION
totrue
ingitlab.rb
(!51906 (merged)) sudo gitlab-ctl reconfigure
Note on Limitations:
- Metrics - #300652 (closed) - will be fixed
- Health Checks are broken - #300661 (closed) (not in work yet)
- Graceful shutdown will not work - should we consider this as an issue and try to fix it?
- Memory Killer is no longer applicable - this seems logical. https://github.com/schneems/puma_worker_killer - docs. I don't think we could find a good workaround, as we will need to restart a full app, which will result in a downtime.
Edited by Aleksei Lipniagov