[op5-users] Check lantency with merlin

[Andreas Ericsson]

Joerg Linge wrote:
> Hi List,
> 
> just tested merlin for about 4 days.
> The check latency rises from 0.2s to 2.3s while merlin is running.
> 
> http://www.pnp4nagios.org/merlin_latency.png
> 
> Is this a known behavior? 
> 

Yes and no. Latency is expected to rise slightly to slightly higher
but equally steady level. This is true as soon as you're loading a
module of any kind. I hadn't expected such a high increase though,
and I would have expected 0.2 to become roughly 0.4 or 0.5, which
seems to hold true for the service check latency. The Merlin module
isn't really doing very much at all, so it's strange that latency
increases so much, and it's *very* strange that it increases such a
lot for host checks but not for service-checks, since the two are
handled in exactly the same way.

I wonder how much of the overhead is in Nagios. Could you try just
inserting a "return 0" at the top of hook_host_result() and the
same at the top of hook_service_result() in hooks.c and see if the
pattern still holds true? If it does, I'll have a peak at Nagios
and see if it does something strange for hostcheck callbacks that
can be optimized. If it doesn't, I'm quite frankly stumped.

> I will update to merlin 0.5 soon. The used Version is a git snapshot from 12.06.09 
> 

Right. Not much has changed between those, so I doubt if it'll
make much of a difference, but testing against latest head is
ofcourse always much appreciated :-)

Thanks for reporting this issue.

-- 
Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

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