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<p class="MsoNormal">Hi All<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We use icinga as a monitoring tool.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We display graphs of switch/router/firewall interface data with the 95% percentile drawn as a line on the graph and the 95% percentile displayed in the legend. The graphs are generated by using pnp4nagios, which if I understand correctly,
is using the rrdtool to extract the data and manipulate it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Recently I found that 95% percentiles were showing on the graph as lower than we expected – especially when I increased the custom time span to more than a certain time period.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I believe that the cause of this is that “If the resolution of the data is higher than the resolution of the graph, the data will be further consolidated (<a href="http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html">http://oss.oetiker.ch/rrdtool/doc/rrdgraph_data.en.html</a>).
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have found out that if I had the following “&w=X” to the url of the pnp4nagios graph, the 95% percentile changes. The 95% percentile continues to increase until the width is 6000 for the particular data in question for a 5 week period
i.e. I assume that at this point the graph is wide enough for there to be no need for data consolidation.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Do you think that I am correct in my assumptions?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">And if that is correct, can I use the rrdtool command line to get the 95% percentile value without any need of generating the graph? i.e. I could be sure that no data consolidation has happened.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Many thanks in advance for your help and please excuse any deficiencies in my knowledge of rrd/pnp4nagios.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">John<o:p></o:p></p>
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