Hmm, you're right. There are moments at which I understand how it works, but I always seem to mix things up when I haven't read the docs for a while. Perhaps a somewhat more verbose explanation at the rrdtool website might help.
Serge. -----Original Message----- From: Thomas Erskine [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 25, 2002 5:49 PM To: Serge Maandag Subject: Re: [rrd-users] Re: Calculating traffic <snip> This isn't the way I understood it, and doesn't agree with my reading of the docs. Here's the description of heartbeat: heartbeat defines the maximum number of seconds that may pass between two updates of this data source before the value of the data source is assumed to be *UNKNOWN*. I don't see where you're getting that it will take 10 values to make one value in the RRD. The RRA (below) says that one incoming primary data point should be used to create one value in the RRD and to keep 100 value. The heartbeat is only used to determine how often you have to update the RRD. A heartbeat of 600 means that you must update it at least every 10 minutes or you'll get unknown values inserted. However, you'll supply new value every 60 seconds and those will create new value, every 60 seconds. The XFF (the 0.5 in the RRA) is for RRAs which do consolidation. An xff of 0.5 means that on half of the values in a given period can be unknown and it will still apply the function (AVERAGE in this case) to the remaining values to produce a consolidated value, but if more than half are unknown, then the consolidated value will also be unknown. This is my understanding of hw it's supposed to work, and it agrees with my experience in using rrdtool. If you find differently, please correct me. -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
