Web interface goes down each morning for few minutes

Hello everyone!

We are making fun office infrastructure, using raspberrypies. One of them is for music - plain volumio, and other is using mmonit to monitor everything to be up and running.

Monit checks all hosts and services each two minutes, making alerts or other actions if something goes down.

Issue i’ve run into is that every day, around 6:30 (GMT +2) web interface stops repsonding for aroud 5 minutes (or two periods around 2 minutes each).
Meanwhile ICMP requests are passing fine.

My first assumption was that there’s something in cron, but cron is disabled by default in volumio and there were no tasks.

Second thing i’ve found: is logrotate, that’s doing log rotation for nginx daily, but disabling

postrotate [ ! -f /var/run/nginx.pid ] || kill -USR1 `cat /var/run/nginx.pid` endscript
didn’t do anything.

This issue is quite annoying (we have sms alerts) , are there any other ideas where to look for it?

Just to know, how is connected the RPI ? wifi or ethernet? When it becomes “dead” how-many time since the last use ?

both rpi’s are connected by wire and are on the same switch.

it’s used every day (playing music for whole day).

As i’ve mentioned, pi is responding to ping requests, but the web interface shuts down for some amount of time. There may be some periodic maintenance script which causing this, but I couldn’t find it.