Since a hour, apache stopped responding. I can reach the server with putty and the average load is only a few percent. Apache is (re)starting without error. If it helps: this morning the server turned itself magically off but in this case it's still on, it worked all day without any further problems.
I have absolutely no idea what to look/search for 🙁
Best Answer
If it were me I'd....
start with top - always the first place to look when things are amiss - is the load average too high? Too low?
next, netstat -nap | less - is the webserver listening on the relevant ports?
if apache is running, then check the webserver logs - is any traffic going through? Anny errors logged?
then the messages log - is the firewall blocking traffic? Is there anything else amiss?
Does the error log show it being shutdown? If not, does the messages log show the oom killer terminating processes?