realistic system requirements and capacity

[Marc Powell]

I'm utilizing a distributed setup and my most heavily loaded data
collector is monitoring PING service on 592 hosts.  It easily completes
all the checks within 5 minutes with minimal load on the server. That
machines is also running Smokeping and Cricket for the same number of
hosts. My data collector machines are PIII 800's with 512MB Ram. Another
data collector which is doing significantly more varied service checks
(ping, http, ntp, dns, smtp, practically the whole gamut along with
several custom plugins we use; 440 services on 206 hosts) is exhibiting
the same performance. Average check execution time is 4.389 seconds and
average check latency is 0.226 seconds. This machine is again also
running Cricket and Smokeping for the same hosts. Not even breaking a
sweat. I feel that I can scale this up 2x or higher on the same
hardware. My only challenge right now is the 4K size of the named pipe
on my central Nagios server and the fact that Nagios doesn't check it
often enough, even with command_check_interval=-1. I'll have periods
when I have 2000+ nsca processes waiting to write to the pipe.

--
Marc

> -----Original Message-----
> From: Russell Adams [mailto:RLAdams at Kelsey-Seybold.com]
> Sent: Wednesday, September 18, 2002 12:34 PM
> To: Nagios-Users (E-mail)
> Subject: Re: [Nagios-users] realistic system requirements and capacity
> 
> I ran Netsaint 0.0.4b on a P90 w/ 64MB for many years, until the load
> levels reached about 300-500% monitoring 120 hosts and 200
> services. Netsaint was still single-threaded, and at this load level
> took about 10-12 minutes to complete each run of service checks...
> 
> I recently upgraded to Netsaint 0.0.7 on a PII/450 w/ 128MB which is
> monitoring 230 hosts and 350 services and its now at about 200%
> load. The parallel checks mean that my service checks are running
> within a fraction of a second of when the scheduler says they should,
> so there's little latency. However the execution time varies by a few
> seconds depending on the load.
> 
> I'm planning on getting a Ghz machine w/ 256MB next to upgrade to
> Nagios.  Even though my server load could increase to monitoring about
> 300+ hosts and 500 services, I think I could handle that on a single
> system still. After that, I would consider doing the distributed
> monitoring. Depends on the number and type of services being
> checked. A ping check takes very little time and resources, and a
> single machine could handle thousands I'm sure. However I'm monitoring
> processes, disks, and more via SNMP, and some other custom shell
> scripts, at about 5-6 services per host. These really load down the
> system, when compared to my 130 ping only checks.
> 
> From my experience, disk space is nearly irrelevant, CPU does all the
> work and some memory can speed it up. I've also heard good things
> about putting your plugins into a RAM disk, but if the machine does
> nothing but Netsaint then I'd think the cache is just as effective
> when there's enough memory available.
> 
> Perhaps this historic data can put your machine selection into
> perspective.
> 
> Russell Adams
> Systems Administrator
> Kelsey Seybold Clinics
> 
> On Wed, Sep 18, 2002 at 08:59:17AM -0700, George Miscioscia wrote:
> > To any and all experienced nagios users, what system requirements
would
> you
> > recommend to run a Nagios install at full capacity, and what would
you
> > consider full capacity before impementing distributed servers? I.E.,
how
> > many checks would you recommend one server perform?
> >
> > thanks,
> >
> > George Miscioscia
> > Manager, Internet Systems
> > Ticketmaster/Citysearch
> > office (213)739-3521
> > cell    (310)902-6743
> >
> >
> >
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> 
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