Howdy ! As discussed on IRC today with Hawson, Bernard et. al. there seem to be a high demand to handle RRD archives in memory out-of-the box from Ganglia. It appears that everyone has his / her own mechanics in place in order to avoid being hit by IO on the gmetad hosts.
After tossing several ideas around we ended up with the following proposal. The idea is to control the RRD archives solely via gmetad.conf, more specifically via the 'rrd_rootdir' variable. It points by default to '/var/lib/ganglia/rrds'. Now, whenever the user modifies this value to something like '/dev/shm/rrds' or 'tmpfs' and then restarts gmetad via '/etc/init.d/gmetad restart' we essentialy move the RRD archive around and potentially alter fstab and issue necessary mount commands. In summary, when gmetad starts up we restore the RRD DB from a FS to memory. When gmetad stops we back it up from memory to a FS. It is debatable wether a cron job should once in a while back up the RRDs in addition to the gmetad start / stop scenario. I have an old backup / restore script from BSD that I can contribute. I also have the init.d script for gmetad with automatic restore / backup for the RRDs. The integration with gmetad.conf and necessary actions to put the tmpfs in place are the missing pieces. Let's discuss how this can be solved best for all possible scenarios. Thanx, Matthias ------------------------------------------------------------------------- SF.Net email is sponsored by: 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 [email protected] https://lists.sourceforge.net/lists/listinfo/ganglia-developers
