Re: [monit] restart service if swap or real ram is below a thresgold

[David Campbell]

Martin Pala wrote:
> Monit monitors just the physical memory usage (no swap).
>
> When the system starts to swap heavily, it is bad for performance no 
> matter how much swap you have. If you know that the memory shortage on 
> you system can be solved by restarting one process, then you should 
> probably check this particular process' memory usage, since there will 
> be most probably relationship. If you are sure that the system wide 
> check is the right solution, the you can use something like this:

Basically I have a memory leak that will be fixed but until then I need 
a short term fix.

> --8<--
>  check system myhost
>     if memory usage > 95% then exec "/bin/pkill badguy"
> --8<--

The problem here surely is that 2.6 Linux kernel will buffer as much 
memory as is needs, so 95% wouldn't that unusual on our servers.

> Or if the badguy is monitored by monit, then:
>
> --8<--
>  check system myhost
>     if memory usage > 95% then exec "/bin/bash -c '/usr/bin/monit 
> restart badguy'"
>
>  check process badguy ...
>   start ...
>   stop ...
> --8<--

Thanks, that is helpful.

Dave