Per the GitLab docs
(https://docs.gitlab.com/ee/install/requirements.html#puma-settings):
> If the operating system has a maximum 2 GB of memory, the recommended number
> of threads is 1. A higher value will result in excess swapping, and decrease
> performance.
and
> In a memory-constrained environment with less than 4GB of RAM available,
> consider disabling Puma Clustered mode.
>
> Configuring Puma by setting the amount of workers to 0 could reduce memory
> usage by hundreds of MB. For details on Puma worker and thread settings, see
> Puma settings.
Luke Granger-Brown
3ea210e884