Checkmk Werk 10402: Deal with RRD sources which are not updated anymore in multiline graphs

ID: 10402 Title: Deal with RRD sources which are not updated anymore in multiline graphs Component: metrics Level: 1 Class: Bug fix Version: 1.7.0i1 The metrics "Guest operating systems" and "CPU time stolen by other operating systems" that appear on the CPU utilization service Check for unix systems are only relevant on virtualized environments. On other cases they are always zero, and thus completely skipped in the graphs, but still tracked by the monitoring core. Checkmk 1.6 stopped delivering this metrics for systems where they are irrelevant. This saves disk space, and disk I/O improving scalability. If you update from Checkmk 1.5, the unused RRDs will remain in disk but won't be updated anymore. If you use the RRD single format you wont experience any problem, but if you are on RRD format for one RRD per metric, the RRDs will go out of sync. At the time of drawing the graphs, this lack of syncronicity will disrupt the resolution of the data, and crash the graphs, if two metrics have a different resolution. With this werk, data is resampled after being retrieved from the core if the metrics on the same graph have different resolutions.