I'm using tmpfs also. My rrds dir is about 188M. I didn't do this because of "problems scaling Gmetad" because it was working fine. But the host also ran Nagios, Cacti and some other stuff, so I wanted to avoid any potential delays in Nagios passive check monitoring.
I have an init script similar to yours. Although I rsync to disk every hour and not every 5 minutes. -Paul Choi Ben Rockwood wrote: > I posted to the list some time ago about problems scaling Gmetad. I > found that after passing some number of monitored nodes I was showing > nodes failed. > > I've finally worked out the issue... my disk was the bottleneck. It > appears that Gmetad serially updates RRDs for a node/cluster. Unable to > tune around this I decided to use tmpfs with a special startup script > and cron job that rsync's the data out of tmpfs every 5 minutes. > > Here's my startup script (executed by SMF on Solaris): > > #!/usr/bin/bash > ## SMF Start method for Gmetad > ## -benr > > if ( mount | grep "/opt/ganglia/data on swap" >/dev/null ) > then > echo "Tmpfs already mounted." > else > echo "Mounting tmpfs..." > chown nobody /opt/ganglia/data > mount -F tmpfs -o size=100m,noxattr swap /opt/ganglia/data > fi > > ## Now sync the data in if its empty: > > if [ -d /opt/ganglia/data/__SummaryInfo__/ ] > then > echo "Cache primed, ready to start." > chown -R nobody /opt/ganglia/data > else > echo "Priming the cache..." > /opt/csw/bin/rsync -at /opt/ganglia/data-disk/ /opt/ganglia/data/ > chown -R nobody /opt/ganglia/data > fi > > ## Finally, start ganglia: > /opt/ganglia/sbin/gmetad > #==================================== > > The cronjob to sync is simple: > > # Sync gmetad ram-disk to physical-disk > # > 5,10,15,20,25,30,35,40,45,50,55,0 * * * * /opt/csw/bin/rsync -at > /opt/ganglia/data/ /opt/ganglia/data-disk/ > > > > > > The question I have for the list is... has anyone else run into this > bottleneck? If so, how did you solve the issue? I know several people > have multiple gmetad's out there, perhaps unnecessarily. CPU usage and > disk consumption are low, its just doing a lot of IO. My data/ dir is > only 27MB. > > benr. > > ------------------------------------------------------------------------- > This SF.net email is sponsored by the 2008 JavaOne(SM) Conference > Don't miss this year's exciting event. There's still time to save $100. > Use priority code J8TL2D2. > http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone > _______________________________________________ > Ganglia-general mailing list > Ganglia-general@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/ganglia-general > > ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Ganglia-general mailing list Ganglia-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-general
