Thanks for the clarification. It seems I did not fully understand the heartbeat feature and its effects on updates :-) I modified my code to account for the short heartbeat and now everything works exactly as planned.
Kind regards, Dirk On Fri, Nov 15, 2013 at 5:11 PM, Simon Hobson <li...@thehobsons.co.uk> wrote: > Dirk wrote: >>I notice some updated values are not always written to my rrdfile by >>rrdcached. The updates do however appear in in the rrdcached daemon >>journal: >> >>Any idea what can be causing this behaviour or what I'm missing? >> >> >>E.g. the update of time 1384516800 is not present in the rrdfile. The >>updates before and after are: > >>Journal Entries: >>rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd >>1384516440:3560054323:2684354508 >>rrd.journal.1384516544.283473:update /var/rrd/0/2/8/test.rrd >>1384516800:3563798323:2684354508 > >>The RDD file is created with perl: >>push @q_array, "/var/rrd/0/2/8/test.rrd"; >>push @q_array, "--step=60"; >>push @q_array, "--start=1352985960"; >>push @q_array, "DS:d_tbs:GAUGE:60:0:U"; >>push @q_array, "DS:u_tbs:GAUGE:60:0:U"; > > Your heartbeat* is too short. Thus when the second update comes it, the > heartbeat expires and the previous period is set to unknown. In this case, > it's been 360s since the previous update which is >> your heartbeat. > You need to reconsider your settings and operation. If you can legitimately > have 360 seconds between updates without invalidating any data, then your > hearbeat must be no less that 360s (deally a little longer). > > The update at 800 is not, in itself, enough to make any bucket of data valid > - in this case it merely ends a period of unknown data and then later updates > will operate correctly (as long as they are frequent enough). Even though you > are using guage data type, RRD does **NOT** store point values. Have a read > of Alex's tutorials athttp://www.vandenbogaerdt.nl/rrdtool/ in particular the > one onRates, normalizing and consolidating. > > * I don't use the perl bindings, but as I read it I think you have 60s as > your heartbeat. > > _______________________________________________ > rrd-users mailing list > rrd-users@lists.oetiker.ch > https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
