Hi guys: See forwarded email below.
Does anybody know why we separate out each metric as a separate rrd file? I understand Cacti also aggregates all the metrics into a single rrd file for the host. Thanks, Bernard ---------- Forwarded message ---------- From: Dmitry B. Bigunayk <[EMAIL PROTECTED]> Date: Mon, Jun 9, 2008 at 11:02 PM Subject: Re: [rrd-developers] rrdupates per second To: Bernard Li <[EMAIL PROTECTED]> Cc: rrd-users <[EMAIL PROTECTED]> > > Thanks for the reply. > > I am one of the developers of Ganglia http://www.ganglia.info. The > issue we have is that once Ganglia starts monitoring past a certain > number of hosts (> 1k nodes), we noticed the system grinds to a halt > with a lot of I/O requests (from rrdupdates). > > Typically Ganglia monitors 32 unique metrics for each host and these > translate to individual rrd files. So with 1k nodes, you essentially > have over 30,000 rrd files that need to be updated periodically. > > The current "workaround" for this issue, is to place the rrd files in > tmpfs. It would be nice to have a better solution than this. > > I did some tests with RRDtool 1.3. While it does provide some I/O > enhancements over 1.2.x, the system with standard 7200RPM SATA HD is > still bogged down by I/O and becomes really sluggish. > > I was wondering if you have any suggestions on how to programmatically > tune the performance? The Ganglia code responsible for doing the > rrdupate is written in C. Our frontend, written in PHP does call > rrdgraph via system call, but that is not really the bottleneck for > us. > > Cheers, > > Bernard > Why you are storing each one unique metrics in separate rrd file? Maybe data collected in different time? I think that the best way to increase performance it's to accumulate metrics from one host in one rrd file. -- Dima: Nosce te ipsum e-mail: [EMAIL PROTECTED] ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
