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</o:shapelayout></xml><![endif]--></head><body lang=EN-NZ link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>This is expected behaviour.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>‘Rrdtool fetch’ will return the raw data, using the RRA that most closely approximates the requested data resolution. So, if you request a resolution of 3600, and only have a 300 RRA available, then this will be used. However, if you have a 3600 RRA then this will be chosen. In addition, RRDTool will ensure the time window is fully covered before selecting a resolution; so you need to be careful of fencepost errors where only the last sample is unavailable at your selected resolution and so it fails back to a lower granularity RRA. The graph function, on the other hand, will perform on-the-fly aggregation and calculation to generate a data set in the required resolution before graphing.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If you want to have the data pre-aggregated, then either ensure that a suitable RRA exists in the RRD, or else use ‘rrdtool xport’, which is like the graph function but returns the data instead (after calculation and aggregation if necessary)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Steve<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Steve Shipway<o:p></o:p></span></b></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>T: +64 9 3737 599 ext 86487<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>E: <a href="mailto:s.shipway@auckland.ac.nz">s.shipway@auckland.ac.nz</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:1.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>(GNU Terry Pratchett)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> rrd-users [mailto:rrd-users-bounces+s.shipway=auckland.ac.nz@lists.oetiker.ch] <b>On Behalf Of </b>Olivier<br><b>Sent:</b> Wednesday, 4 November 2015 5:29 a.m.<br><b>To:</b> rrd-users@lists.oetiker.ch<br><b>Subject:</b> [rrd-users] RRDTool lib fetch<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Hello,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I'm looking for documentation on rrdtool library. I'm actually using it through PHP and PECL project. I'm using function rrd_fetch() to grab data from a specific .rrd file.<br><br>I can see that 'resolution' parameter is not respected (as rrd_graph is doing) : RRD seems to find the most accurate resolution available, but returns the raw data. For example, if I have data with resolution =60 and I request resolution =3600, data is not aggregated, and I have one row every minute instead of one per hour.<br><br>First, I want to know if this is an expected behaviour. In that case, it means that rrd_graph is doing this aggregate itself. Is there a way to ask rrdtool to do the math for me ?<o:p></o:p></p></div><div><p class=MsoNormal><br><br>Olivier<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div></body></html>