> If you log data at irregular intervals, then you'll get three effects. > 1. Data normalisation - your samples will be modified to fit into the RRD's > interval. This is common; however for small values, this can cause problems, > particularly if you are interested in the actual values and not the rate. > This is indeed the case with some of my logging.
> 2. XFF making RRA cdps unknown. If you have insufficient samples in an > interval, then an RRA may set the value for that cdp to unknown. > 3. Heartbeat making data points unknown. This is your biggest risk. You > MUST have a sample AT LEAST as often as the heartbeat. If the heartbeat is > smaller than your interval, then an interval will be set to unknown unless > multiple values are received during it. If your heartbeat is exceptionally > large, then one sample may case several data points to be created! This can > be strange. > > You could, for example, log the total number of bounced packets on a regular > basis. This would work. Or, every (regular) interval, log the number of > packets bounced since the last update. What you should not do is to only log > something if and when you bounce a packet. > All noted, thanks. I will then revert back to the "old" way, with a bit of a twist - executing the sampling at regular intervals, but via a special daemon and log the results (including zero/no matches) to RRD. That way, the database should be OK and kept in a sane state. Thanks Steve! _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
