I've been trying to minimise number of running processes on serve and because I'm not monitoring anything straight over the server I've decided to change in server settings StartPollers=0.

After this I found that all zabbix server internal items stopped produce new monitoring data and all calculated items stopped be updated.

I think that StartPollers=0 in server settings should be forbidden or at least some message in logs should be produced that with StartPollers=0 calculated items and internal metrics no longer will be updated.

Looks like nowhere in zabbix doic is documented that poller processes are responsible for sampling that types of of items so probably it would be good to at least put document this behaviour.