Apache mpm prefork config mismatches postgres default max connections

[JoKre17]

Hello everyone,

first of all my configuration:
I am running the latest version of the docker image on my TrueNAS Scale instance as an automatically deployed app that comes with a postgres DB (Postgres 13) and the nextcloud container running apache service.

The output of occ config:list system is included below.

The issue I have run into is nextcloud logging that all database connections are used up and any further connections are reserved for super users. This issue came up during browsing of external storage content with folders including hundreds of photos.

I believe the misconfiguration is in the apache mpm prefork config that defaults to something like this:

# prefork MPM
# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# MaxRequestWorkers: maximum number of server processes allowed to start
# MaxConnectionsPerChild: maximum number of requests a server process serves

StartServers            5
MinSpareServers         5
MaxSpareServers         10
MaxRequestWorkers       150
MaxConnectionsPerChild  0

while the postgres instance per default only allows up to 100 connections total.
The idea from ChatGPT was to reduce the MaxRequestWorkers from 150 to 50, but effectively one could also increase the amount of connections postgres handles from 100 to ~160 (-3 reserved for superuser) for example.
In my case I will change the postgres setting as the apache setting does not persist across container restarts, but a permanent solution to this issue would be great!

Here now the content of the command occ config:list system:

{
    "system": {
        "htaccess.RewriteBase": "\/",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "upgrade.disable-web": true,
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "31.0.7.1",
        "forwarded_for_headers": [
            "HTTP_X_FORWARDED_FOR"
        ],
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "overwrite.protocol": "https",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "loglevel": 2,
        "maintenance": false,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "127.0.0.1",
            "localhost",
            "nextcloud",
            "***REMOVED SENSITIVE VALUE***"
        ]
    }
}