petecooper Wrote:
-------------------------------------------------------
> Hello.
> I have a single-digit fleet of Ubuntu servers, all running a similar
> configuration:
>
> * Ubuntu 20.04LTS, current kernel via `apt`
> * Nginx 1.23.1 from source, with 3rd party modules
> * PHP 8.0 or 8.1 from source
>
> One of the servers has recently had issues with what appears to be an
> Nginx segfault, which manifests as high CPU load, repeated `apport`
> processes spawning, and errors written to `apport.log`. The other
> servers have a similar config, but are not affected by this issue.

[…]

The issue is resolved with the removal of third party module `nchan` [1]. A recent release resolved a reported issue with Nginx 1.23, but given the number of modules I am using it's possible there may be a conflict with another module.

Thank you Sergey A Osokin for your assistance and expertise.

[1] https://github.com/slact/nchan