Hi,
On 15-12-11 17:58, Simon Hobson wrote: >> We have an annoying problem. (...) >> However, as this runs on crontab, we have now end up with a situation >> where a lot of .rrd files (thousands) where created at the same time of >> the day. The result is that the "data aggregation" process of all these >> .rrd files start at roughly the same time; and this causes disk IO >> congestion. > I doubt it. RRD tool does not aggregate data based on arbitrary times > (eg file creation). Aggregation (consolidation/normalisation) is done > when data is entered, and all consolidated time periods are an > integer multiple of the period size since unix epoch (midnight, 1st > Jan 1970). (...) > Basically, every time you do an update, rrd tool will update all > consolidated time periods which have ended since the last update. > Thus if you run a script once a day at 1am, it will close the 24 hour > consolidation for the previous day regardless of what time of day the > file was created. It would also update and close 12 2 hour > consolidation periods for the previous day. OK, I get it. I did notice all .rrd files had a timestamp for the 24h stats at 2 AM CEST/1AM CET (midnight UTC). Hmm. As most script run either somewhere between every 5 to 15 minutes; all rrd files (over 10000) do the "24h consolidation" at the same time. There is no solution for that. Cheerio! Kr. Bonne. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
