On Thursday 04 October 2007 12:27:41 john allspaw wrote: > As to compatability breakage....it would suck to lose data, for sure.
As far as I understand it, the compatibility issue is mostly between gmond and gmetad rather than RRDTool. The consequence is one would have to upgrade all of a site in one go. The underlying storage is RRDTool's rrd files. Provided the version of rrdtool don't change and the filename remain the same, there's no issue with loss of data. If this patch going into trunk [1], metrics that contain a percent symbol *in the metric name* (independent of units) will change corresponding filename. This is unavoidable, due to the markup. [1] http://bugzilla.ganglia.info/cgi-bin/bugzilla/show_bug.cgi?id=120 Does anyone actually have metrics with percent symbols in the name? If so, perhaps a transition script could help by renaming these files. > So > how about maybe adding a way to possibly archive past data ? Possibly > freeze the data you have before upgrade, and then have it available as a > separate item, just never to be updated again ? Loosing data shouldn't be a problem (with the %-in-filename caveate). More of an issue is when the meaning of a metric's numbers changes (e.g. disk_free numbers are in Bytes, not GB). If this happens then a migration script could dump the historic data (using the "rrdtool dump" command), modify the data and import it back into an rrd file. Cheers, Paul. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
