<![CDATA[1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM]]>Hi,

the 1.117.2 update introduced scaling Puma workers to the processor count. On my server with 12 cores this changed the worker count from the previous default of 3 to 12 — a 4x increase in RAM consumption, causing repeated OOM kills.

Setup:

  • Cloudron 9.2.0
  • GitLab 1.117.2
  • 12 CPU cores, 24GB RAM total
  • Small team, ~5 active users

What happened:
Before 1.117.2, GitLab ran stably for years with 7GB RAM limit (3 Puma workers by default via puma.rb). After the update, GitLab immediately started hitting OOM repeatedly — even after raising the memory limit to 14GB, it still consumed 13.99GB and got killed.

The root cause is in start.sh:

cpus=$(nproc 2>/dev/null || echo 2)
export PUMA_WORKERS=$(( cpus < 2 ? 2 : cpus ))

On a 12-core server this sets 12 Puma workers. Each worker consumes ~800MB–1GB RAM, so Puma alone needs ~12GB — before Gitaly, Sidekiq and Redis are counted.

Suggestion:
Either cap PUMA_WORKERS at a reasonable maximum (e.g. 4–6), or provide a way to override it via /app/data/ so admins can tune it for their setup.

Is there a recommended workaround in the meantime?

Thanks

]]>https://forum.cloudron.io/topic/15687/1.117.2-scale-puma-worker-count-to-processor-count-causes-oom-on-multi-core-servers-with-limited-ramRSS for NodeSun, 19 Jul 2026 20:53:14 GMTTue, 07 Jul 2026 15:47:43 GMT60<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Tue, 14 Jul 2026 15:14:55 GMT]]>@simon yeah, that makes sense. I think I will just cap it for all instances to 4.

]]>https://forum.cloudron.io/post/126771https://forum.cloudron.io/post/126771Tue, 14 Jul 2026 15:14:55 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Tue, 14 Jul 2026 07:17:07 GMT]]>Update on our end:
After the fix in 1.117.2/1.117.3, GitLab starts correctly and the worker count scales with available memory. On our 12-core server with 9.25GB assigned, we get 7 workers — which is mathematically correct per the formula.
However we keep getting OOM kills after several hours. With 7 workers × ~1GB each, plus Gitaly, Sidekiq and Redis, the container is consistently running at 85-90% of its limit. There's no headroom for load spikes.
The formula mem_gb - 2 assumes ~1GB per worker, but in practice workers grow beyond that under real load. Would it make sense to use a more conservative formula, e.g. mem_gb / 2 or capping at 4 workers for instances with fewer than 20 users?

]]>https://forum.cloudron.io/post/126748https://forum.cloudron.io/post/126748Tue, 14 Jul 2026 07:17:07 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 15:17:08 GMT]]>Thank you. This solved it.

]]>https://forum.cloudron.io/post/126560https://forum.cloudron.io/post/126560Wed, 08 Jul 2026 15:17:08 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 11:53:09 GMT]]>Hello @simon
We just published an update for the @gitlab app that reduces the puma work count.

]]>https://forum.cloudron.io/post/126548https://forum.cloudron.io/post/126548Wed, 08 Jul 2026 11:53:09 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 10:08:39 GMT]]>Even with 18 GiB of RAM allocated to GitLab, I’m constantly seeing OOM messages. So a quick fix would be great.

]]>https://forum.cloudron.io/post/126541https://forum.cloudron.io/post/126541Wed, 08 Jul 2026 10:08:39 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 06:44:31 GMT]]>Yeah, we had this our gitlab instance too. I am fixing this now @simon

]]>https://forum.cloudron.io/post/126535https://forum.cloudron.io/post/126535Wed, 08 Jul 2026 06:44:31 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 06:13:04 GMT]]>I also checked start.sh for any hook mechanism (sourcing a custom file from /app/data/ etc.), there is none. So there is currently no supported way for end users to override PUMA_WORKERS without modifying read-only container files.

A fix would need to come from the package itself, for example by capping the worker count or by reading an override from /app/data/ like:

PUMA_WORKERS=$(( cpus < 2 ? 2 : cpus ))
[[ -f /app/data/puma_workers ]] && PUMA_WORKERS=$(cat /app/data/puma_workers)
export PUMA_WORKERS

Until then, the only workaround is raising the memory limit in Cloudron significantly. On a 12-core server this means ~14-18GB just for GitLab!

]]>https://forum.cloudron.io/post/126527https://forum.cloudron.io/post/126527Wed, 08 Jul 2026 06:13:04 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Wed, 08 Jul 2026 06:08:54 GMT]]>Thanks for the hint
The GitLab docs describe configuring Puma via /etc/gitlab/gitlab.rb, but the Cloudron package doesn't use Omnibus — it has its own Docker-based setup with gitlab.yml and a start.sh script.

In start.sh, the worker count is set like this:

cpus=$(nproc 2>/dev/null || echo 2)
export PUMA_WORKERS=$(( cpus < 2 ? 2 : cpus ))

Since start.sh is read-only inside the container, I can't override PUMA_WORKERS directly. Is there a supported way in the Cloudron GitLab package to override this — for example via a file in /app/data/ or a similar mechanism?

]]>https://forum.cloudron.io/post/126526https://forum.cloudron.io/post/126526Wed, 08 Jul 2026 06:08:54 GMT<![CDATA[Reply to 1.117.2 - "scale puma worker count to processor count" causes OOM on multi-core servers with limited RAM on Tue, 07 Jul 2026 16:03:07 GMT]]>Hello @simon
Thanks for reporting.
It should be possible to limit the ram usage of the puma workers according to https://docs.gitlab.com/administration/operations/puma/

]]>https://forum.cloudron.io/post/126514https://forum.cloudron.io/post/126514Tue, 07 Jul 2026 16:03:07 GMT