You MUST recompile PHP with a larger value of FD_SETSIZE. It is set to 1024

[asolonytskyi]

Hi! Found interesting issue with websocket server. When server working in Docker.

Sometimes get next error:

stream_select(): You MUST recompile PHP with a larger value of FD_SETSIZE.
It is set to 1024, but you have descriptors numbered at least as high as 1024.
 --enable-fd-setsize=2048 is recommended, but you may want to set it
to equal the maximum number of open files supported by your system,
in order to avoid seeing this error again at a later date.

Preconditions:

• command: websockets:serve
• php: 8.1.16
• Linux: 5.10.215-203.850.amzn2.x86_64
• Docker image: php:8.1.16-fpm-bullseye

I tried next:

1. recompilate php with param --enable-fd-setsize=65536
2. up ulimit
3. up filediscriptor on server

But steal doesn't work..