nginx `worker_processes = auto` is wrong in k8s about docker-php HOT 3 CLOSED

This issue seems like it might be deeper in the NGINX configuration, correct?

I am providing the defaults of NGINX and the steps to reproduce are pretty vague -- especially for people who don't run K8s everyday.

Are you aware of any NGINX directives that need to be changed?

from docker-php.

Closing for inactivity. Feel free to publish replication steps if you'd like to see this re-opened.

from docker-php.

I did write a response. But it's not here. Don't know what happened.. This is not specific to k8s.

"worker_processes auto;" won't work as you think it should inside cgroups-controlled environment (such as docker or lxc or whatelse).

nginx relies on sysconf(_SC_NPROCESSORS_ONLN) call to determine the number of available CPUs to spawn the workers accordingly. Unfortunately in cgroups this does not work and the number of CPUs is not changing whether you define a cpu subset or not.

So it's a cgroup thing, not kubernetes. "auto" will always use the number of cores available to the underlying host wether it's a VM or bare-metal, it won't use the limits set by cgroup or cgroup2.

It's harder to mimic this problem in MacOS since Docker/Podman creates a virtual machine with limited resources for the Docker/Podman container. But in a real prod environment running on Linux you should be able to replicate this issue. Doesn't need to be a k8s cluster. You can run a cheap virtual machine with 2 cores and start a docker container inside it that is limited to use 1 core, you will see two worker processes inside the running container.

from docker-php.