[rrd-users] rrd and collectl

[Mark Seger]

I had posted a note to this list some time ago about collectl 
http://collectl.sourceforge.net/ and its use as a source of data for rrd 
and while I have had a few notes of mild interest I thought I'd try 
again since collectl is becoming better known and is even now part of 
fedora.  As with all monitoring situations, everyone has different needs 
and I've always tried to address as many as possible with collectl.

For example, rrd recognizes the importance of finer granularity for more 
recent data but I doubt it could handle what collectl produces - 
hundreds of samples every 10 seconds or even more frequently, down to 
fractions of seconds if you prefer.  Maybe for a couple of nodes, but 
hundreds or thousands?  But collectl has a number of mechanisms to deal 
with a lot of different situations and perhaps the answer to this 
situation is to have collectl save all its data locally and only pass a 
subset (perhaps at a different frequency) up to rrd.  Then someone could 
use rrd to monitor a cluster and if a problem arises dive deeper into 
collectl's local data?  Just a thought.  Then again someone who knows 
rrd better might have a better solution.

In any event, collectl has the ability to pass results over a socket or 
even write a current snapshot to a small file that another tool can pick 
up at its convenience.  In fact, collectl can even write its output in 
rrd format if that's what someone is looking for, but as I said I fear 
there may just be too much data.

So if anyone does have any interest, check out what collectl can collect 
and if there is any interest in using it to feed rrd, let's talk...

-mark