[rrd-developers] Accelerator Daemon

[Tobias Oetiker]

Scott,

Yesterday Scott Brumbaugh wrote:

> Hi Florian,
>
> On Mon, Jun 30, 2008 at 10:52:23AM +0200, Florian Forster wrote:
> > Hi Scott,
> >
> > thanks for your feedback, I really appreciate it :)
> >
> > On Sun, Jun 29, 2008 at 02:21:10PM -0700, Scott Brumbaugh wrote:
> > > When a large number of rrd updates occur at the same time the
> > > filesystem tries to write all updates to disk file at the same time.
> > > This slows the system.  I may be missing something but it looks like
> > > that will happen with this patch if a client is both writing and
> > > reading large numbers of rrd files simultaneously.
> >
> > Yes, that's probably right. I didn't expect anyone with such a huge
> > number of RRD files to generate graphs periodically/statically instead
> > of on demand/dynamically.. Is anyone with a big number of files doing
> > that? If so: Why?
> >
>
> Graphing isn't the only use for the data in the rrd files.  For large
> networks visually watching graphs for anomalies don't scale well.  At
> some point there will just be too many graphs to watch.
>
> Rrdtool allows for automated network monitoring through the rrd_xport
> function.  You can readout the current rate estimates and use them to
> update filters to do automated monitoring.  For this type of
> application it is good to be able to read out the last few rate
> estimates quickly after an update.

for monitoring, it is not very efficient to pull data back out of
rrd files ... what you should do, is to use updatev (I wonder how
the accelerator daemon deals with that one) and then take the
output todo your monitoring on the fly ... this is MUCH more
efficient.

cheers
tobi
>
>
>
> Scott B
>
>
>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900