[LRUG] Sites drop off web

[Andrew Stewart]

On 22 Jul 2011, at 11:38, George Ornbo wrote:
> I'd go through a process of elimination here, but seems like it might
> be related to an unknown cron task consuming too much memory on a low
> memory VPS
> 
> * It could be a network issue with the hosts so I'd get them to
> confirm there are no known issues

I'll check.

> * It could be a DNS issues so get your DNS provider to confirm there
> are no known issues

I'll check.

> * It could be another service using cron. Check /etc/cron/cron.daily
> and anything in /etc/cron/*

Did that.  /etc/cron.daily contains logrotate, makewhatis.cron, mlocate.cron, and rpm.

Since cron.daily is run at 23.02 VPS time, or 4.02am UK time, I ruled it out.  Something would have to consistently take 30min to run to be a candidate for my problem.  This seems unlikely.

> * It could be an OS level issue /var/log/syslog
> * It could be a hardware issue /var/log/dmesg

I looked in all the files in /var/log accessed after 23.25 VPS time.  They were:

wtmp
lastlog
cron
secure
messages

Of these, the first two were binary so I couldn't inspect them.  The others had nothing around the time in question.

> * It could be your server running out of memory. You can set Monit up
> to tell you if memory is running out. logrotate *might* cause memory
> to run out.
> * It could be your server stack crapping out. I'd use something like
> Monit to tell you if a server process dies.

Monit is already set up to notify me if a process of interest dies, but it hasn't told me about anything.

Thanks for all the ideas!

Cheers,
Andy

-------
http://airbladesoftware.com