Re: OT: Munin (was Re: Determining server load from client)

On Mar 21, 2007, at 4:13 PM, Tobias Brox wrote:

> [Erik Jones - Wed at 09:31:48AM -0500]
>> I use cacti (http://cacti.net) which does the same thing that munin
>> does but in php instead. Here's what I use to db stats to it (again,
>> php):
>
> I haven't tried cacti, but our sysadm has done a little bit of
> research
> and concluded "cacti is better". Maybe some day we'll move over.
>
> Munin is generating all the graphs statically every fifth minute,
> while
> cacti generates them on demand as far as I've understood. The munin
> approach is pretty bloat, since one usually would watch the graphs
> much
> more seldom than what they are generated (at least, we do). That's
> not
> really an argument since CPU is cheap nowadays - but a real
> argument is
> that the munin approach is less flexible. One would like to adjust
> the
> graph (like, min/max values for both axis) while watching quite some
> times.

Well, by "default", Cacti polls all of the data sources you've set up
every five minutes as well as that's how the docs instruct you to set
up the cron job for the poller. However, with a little understanding
of how the rrdtool rras work, you could definitely poll more often
and simply edit the existing rras and datasources to expect that or
create new ones. And, yes, the graph customization is pretty cool
although for the most part the just map what's available from the
rrdtool graph functionality. If you do decide to set up Cacti I
suggest you go straight to the faq section of the manual and read the
part about going from a simple script to a graph. The main manual is
almost entirely centered on the built-in networking (e.g. snmp) data
sources and, as such, doesn't do much for explaining how to set up
other data sources.

erik jones <erik(at)myemma(dot)com>
software developer
615-296-0838
emma(r)