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<p class="MsoNormal"><span lang="EN-GB">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">we use rrd to get an overview of our server farm. Every data point that is monitored (disk usage, cpu, mem, temp., iops, bandwidth and so on) gets written to rrd (and then gets visualized via drraw).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Every now and then we get some timeout from the monitoring system (read: a missing data point), but i’m unable to implement this in RRD.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Minimal compiling sample:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">-------------------------------------------------------------------------------<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rm test.rrd<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool create test.rrd --step 300 --start 1477432800 DS:testds:GAUGE:300:U:U RRA:LAST:0:1:10<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool update test.rrd 1477433100:12<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool update test.rrd 1477433400:13<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool update test.rrd 1477433700:15<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"># rrdtool update test.rrd 1477434000:NaN # here is a missed measuring point<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool update test.rrd 1477434300:8<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool update test.rrd 1477434600:12<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">-------------------------------------------------------------------------------<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">As you can see, the data point for the timestamp 1477434000 will not be written to rrd, but the following data point is available, again.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">But if you dump the rrd, you can notice some strange behaviour:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">rrdtool dump test.rrd | grep "2016-10-26 00"<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:00:00 CEST / 1477432800 --> <row><v>NaN</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:05:00 CEST / 1477433100 --> <row><v>1.2000000000e+01</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:10:00 CEST / 1477433400 --> <row><v>1.3000000000e+01</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:15:00 CEST / 1477433700 --> <row><v>1.5000000000e+01</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:20:00 CEST / 1477434000 --> <row><v>NaN</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:25:00 CEST / 1477434300 --> <row><v>NaN</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <!-- 2016-10-26 00:30:00 CEST / 1477434600 --> <row><v>1.2000000000e+01</v></row><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">1477432800 is missing, because we did not populate it with data.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">1477434000 is missing, because there was a timeout<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">But why the heck is 1477434300 missing? We populated it with value 8.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Considerations regarding the definitions:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Step=300, because we check every 5 minutes<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Heartbeat=300, because rrd shall not interpolate<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Xff=0, if one PDP is missing, I want to see an NaN<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Can anyone advise how to setup the rrd, so that one missing PDP gets exactly one NaN ?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Thank you very much!<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Friedhelm<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
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<font size="-2">CEWE Stiftung & Co. KGaA mit Sitz in Oldenburg; Registergericht Oldenburg HR B 208214; Persönlich haftende geschäftsführende und vertretungsberechtigte Gesellschafterin:<br>
Neumüller CEWE COLOR Stiftung, Sitz: Oldenburg;<br>
Stiftungsverzeichnis der rechtsfähigen Stiftungen des bürgerlichen Rechts im Bezirk der Regierungsvertretung Oldenburg Nummer 15(034).<br>
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