====== Issue ======

=====  Too many open files =====

Some request returns 404 and error is logged in ''error.log''
<code>
[crit] 124477#124477: accept4() failed (24: Too many open files)
</code>

https://www.cyberciti.biz/faq/linux-unix-nginx-too-many-open-files/

===== nginx: [warn] protocol options redefined for 0.0.0.0:443 =====

Nginx ''1.23.4'' introduces listen directive consistency check between all config files.

All ''listen 443'' directives must be with the same options. So example below shows incorrect configuration:
<code>
# in some files:
listen 443 ssl http2;

# in another:
listen 443 ssl;
</code>
So check every virtualhost config file and also ''/nginx/conf.d/default.conf''

More:
  * [[https://serverfault.com/questions/1131318/nginx-warn-protocol-options-redefined|nginx: [warn] protocol options redefined]]
  * [[https://github.com/nginx/nginx/commit/dad65f3e449f215469943628f2b1f12a118fcf7e|Added warning about redefinition of listen socket protocol options.]]
  * [[https://www.mail-archive.com/nginx@nginx.org/msg24883.html|NGINX 1.23.4 warning message]]