hi<br><br>i am brand new to rrd and was wondering if rrd can help me with the following situation, i have two time series:<br><br>1. concurrent users/time<br>2. connections/time<br><br>it is not obvious in this hypothetical example but in my situation i am not able to sample my data from the same place, so each series is sampled against it's own timeframe at roughly the same interval (2 seconds). now i want graph connections vs users. according to the documentation rrdtool is able to interpolate the datasets, so effectively i assume it should be able to merge these datasets when i insert them into the same rrd. i created a rrd like this:
<br><br>rrdtool create user-rra-max-registerGroup.rrd --start 1176840612 --step 2 DS:user:GAUGE:15:0:10000 DS:connections:GAUGE:15:0:10000 RRA:AVERAGE:0.2:2:256<br><br>i insert each series of data independently with a perl script, basically calling:
<br><br>rrdtool update my.rrd -t user $timestamp:$users<br>rrdtool update my.rrd -t connections $timestamp:$connections<br><br>these two series' of data was captured at overlapping time, however after the insert fetching from the db they appear to be mutually exclusive:
<br><br>1176842132: 3.0200000000e+02 nan<br>1176842136: 3.0275000000e+02 nan<br>1176842140: 3.0300000000e+02 nan <--- users ends here<br>1176842144: nan 4.7055000000e+03 <--- connections starts here<br>1176842148: nan
8.1140000000e+03<br>1176842152: nan 3.4725000000e+03<br><br>even though the connections series started earlier in time.<br><br>am i misunderstanding what rrdtool can do?<br><br>thanks<br>peter<br><br>