My organization wants to record more detailed information for longer periods of time without consuming excessive resources on the server performing RRD operations and storing RRD files. I know RRD files maintain the same size on disk after creation. However, I'm unsure how the number of RRAs and RRA step/row values affect CPU, disk I/O, and memory resources particularly during update operations and periodic internal consolidations. Further complicating the situation, each graphing application manages RRD files differently. For example, Zenoss creates one RRD file with a single DS and associated RRAs for each OID retrieved from a device. Retrieving just a few OIDs from a large number of devices results in Zenoss operating on many small RRD files per update cycle. I haven't found a way to configure it otherwise. On the other hand, Cacti creates one RRD file with a variable number of DS based on templates. I can configure and implement these templates to perform roughly the opposite management style of Zenoss by increasing the size and complexity of each RRD file, but reducing the overall number of them. I know discussion of Zenoss vs. Cacti wanders off-topic, but in this case providing the methods they use for managing RRD files may greatly affect answers to my primary question.
I currently use Zenoss to retrieve about 11000 OIDs every 5 minutes. Each of the 11000 RRD files contains 4 RRAs providing data for about 2 days at 5 minute intervals (essentially no consolidation), 2 weeks at 30 minute intervals, 50 days at 2 hour intervals, and 600 days at 1 day intervals. What sort of effects on CPU, disk I/O, and memory resources can I anticipate during update and periodic internal consolidations if, for example, I change these RRAs to 1 year at 5 minute intervals (essentially no consolidation), 2 years at 1 hour intervals, and 3 years at 1 day intervals? Can anyone provide a formula or general way to estimate resource consumption for various RRA configurations? When confronting resource issues, which forms of RRD tuning (e.g., increasing RRA steps, reducing RRA rows, or even eliminating RRAs) provide the most effect? I'm also somewhat interested in determining how various RRA configurations might affect resources needed for graph operations. Thanks, Matt _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users