check_icmp

[Bergström Sebastian]

> Yes. It's a lot faster (especially for detecting down hosts), 
> more portable ("unable to parse ping output" goes away), it 
> requires less memory (fewer fork()'s = fewer PTE's and fewer 
> task-structures) and has more features. You can f.e. set TTL 
> on outgoing packets, meaning you can monitor which of several 
> redundant routes is being used, and if BGP fucks up and 
> starts routing your traffic through a nearby continent you'll 
> know it soon enough.
> 
> Also, it's a very common plugin to use, as nearly everybody 
> use ping to find out if their hosts are up (and usually as a 
> service as well). Even a minor speed increase in this plugin 
> can make a dramatic change in nagios performance. Especially 
> with network outages, where the usual check_ping would get 
> ICMP_HOSTUNREACH several times, whereas check_icmp drops the 
> target immediately upon such a reply and deemes it dead 
> (saves roughly 12 seconds per hostcheck with identical 
> default configurations).

Sounds superb!

> > I know that check_ping has a weird problem of timing out 
> everynow and 
> > then, even with increased host_check_timeout values...
> > 
> 
> I don't know about that. I've been using check_icmp since version 0.6.

I will definitively implement check_icmp and look for improvements.
My problem might just be that I have a pretty slow machine related to the number
of checks performed (currently running 222 service checks - will grow to around
1.000 soon enough).

Does anyone have recommendations for what kind of machine (processor, RAM etc)
one needs for a certain amount of checks? I see the problem in this question
since a service check can be quick and light as well as slow and big.
I'm currently using NSClient and ping service checks only.
I tried to look this up once we decided to implement Nagios, however,
I didn't find anything useful.
Any hints are deeply appreciated.


----------------------------------------------
Sebastian Bergstroem
Technical coordinator
Kunskapsskolan i Sverige AB
sebastian.bergstroem at kunskapsskolan.se
----------------------------------------------- 

> -----Original Message-----
> From: Andreas Ericsson [mailto:ae at op5.se] 
> Sent: den 8 februari 2005 14:16
> To: nagios-users at lists.sourceforge.net
> Subject: Re: [Nagios-users] check_icmp
> 
> Bergström Sebastian wrote:
> > Thanks! That truly answers most of my questions.
> > 
> > What is the reason that you made check_icmp a drop-in 
> replacement for 
> > _ping? Is it that much better?
> > 
> 
> Yes. It's a lot faster (especially for detecting down hosts), 
> more portable ("unable to parse ping output" goes away), it 
> requires less memory (fewer fork()'s = fewer PTE's and fewer 
> task-structures) and has more features. You can f.e. set TTL 
> on outgoing packets, meaning you can monitor which of several 
> redundant routes is being used, and if BGP fucks up and 
> starts routing your traffic through a nearby continent you'll 
> know it soon enough.
> 
> Also, it's a very common plugin to use, as nearly everybody 
> use ping to find out if their hosts are up (and usually as a 
> service as well). Even a minor speed increase in this plugin 
> can make a dramatic change in nagios performance. Especially 
> with network outages, where the usual check_ping would get 
> ICMP_HOSTUNREACH several times, whereas check_icmp drops the 
> target immediately upon such a reply and deemes it dead 
> (saves roughly 12 seconds per hostcheck with identical 
> default configurations).
> 
> > I know that check_ping has a weird problem of timing out 
> everynow and 
> > then, even with increased host_check_timeout values...
> > 
> 
> I don't know about that. I've been using check_icmp since version 0.6.
> 
> -- 
> Andreas Ericsson                   andreas.ericsson at op5.se
> OP5 AB                             www.op5.se
> Lead Developer
> 
> 
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide Read honest & 
> candid reviews on hundreds of IT Products from real users.
> Discover which products truly live up to the hype. Start reading now.
> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> _______________________________________________
> Nagios-users mailing list
> Nagios-users at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/nagios-users
> ::: Please include Nagios version, plugin version (-v) and OS 
> when reporting any issue. 
> ::: Messages without supporting info will risk being sent to /dev/null
> 
> 


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_ide95&alloc_id396&op=click
_______________________________________________
Nagios-users mailing list
Nagios-users at lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nagios-users
::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. 
::: Messages without supporting info will risk being sent to /dev/null