I'm trying to use rrdtool to monitor an array of machines on a LAN, using a script that queries them via SNMP. I've got rrdtool 1.2.6 (Linux/2.6.14) to store and graph the data, so far so good.
Now I've discovered a problem with values supposed to be unknown (channels not being updated because the corresponding computers are down): they don't show up as unknown/NaN in the database - instead they are zero. My database looks like this (only three channels here, to make it easier): rrdtool create /var/rrd/traffic/node-in-traffic --start N --step 10 DS:syslab-00- nicin:COUNTER:100:U:U DS:syslab-01-nicin:COUNTER:100:U:U DS:syslab-02- nicin:COUNTER:100:U:U RRA:AVERAGE:0.5:1:480 RRA:AVERAGE:0.5:6:2520 RRA:AVERAGE:0.5:60:2016 and when, let's say, the first one of the computers (DS "syslab-00-nicin") is down, the update command being issued by my script would look like this: rrdtool update /var/rrd/traffic/node-in-traffic -t syslab-02-nicin:syslab-01-nicin 68650972:369163891 As I interpret the documentation, the first column (syslab-00-nicin) should be filled with NaN, since no data is ever coming in - but it has zeros instead. This creates problems particularly if zero cannot intuitively be related to a box being down (for network traffic it makes sense, for cpu idle% it doesn't really). Does anyone have any ideas? I've been trying a lot of things and potential workarounds, but it seems I got stuck here. Oliver -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://lists.ee.ethz.ch/rrd-users WebAdmin http://lists.ee.ethz.ch/lsg2.cgi
