Apache MaxRequestWorkers 150 instead of 6 — recurring OOM

[maxkreg]

Hey All,

we are seeing recurring out-of-memory restarts on one of our WordPress (Managed) apps and, after some investigation, believe the app is not applying the package's own Apache worker limit. I would appreciate your help getting this corrected.

The container OOMs roughly twice a day. During the last event, apphealthmonitor logged the OOM at 2026-09-02 10:32:37 UTC, with CPU peaking around 540% and memory at 100%. Baseline memory is only about 0.5 GB, so the app is healthy until a short burst of concurrent requests hits it.

What we found:

Apache (mpm_prefork, mod_php) is running with the Ubuntu default MaxRequestWorkers 150, not the managed default of 6:

$ ls -l /etc/apache2/mods-enabled/mpm_prefork.conf
... /etc/apache2/mods-enabled/mpm_prefork.conf -> ../mods-available/mpm_prefork.conf
$ grep MaxRequestWorkers "$(readlink -f /etc/apache2/mods-enabled/mpm_prefork.conf)"
MaxRequestWorkers       150

At the same time, /app/data/apache/mpm_prefork.conf does contain the expected managed values (StartServers 2, MaxSpareServers 3, MaxRequestWorkers 6, MaxConnectionsPerChild 100), but this file is clearly not being applied to the running Apache.

With 150 workers allowed and each mod_php worker using roughly 200 MB with our plugin stack, about 20 concurrent requests are enough to exhaust the container and trigger the OOM. With the intended cap of 6 workers this could not happen, we think.

A plain restart and the memory change from 3 to 4 GB did not restore the 6-worker limit, so this looks to us like it needs to be corrected at the package or instance level (?).
The issue is reproducible, and we are more than happy to give you access or run any diagnostics you need.

Thanks very much for your help!

[girish]

@maxkreg great catch. Update is coming - https://git.cloudron.io/packages/wordpress-managed-app/-/merge_requests/37

[maxkreg]

@girish Awesome, thanks for your efforts and quick response as always!