New user of rrdtool.<br><br>I plan on graphing the number of hits I get each day on my webserver.<br><br>I have logs going back over a year, so my RRD will be backdated many months back and I will populate it with a script that parses my weblogs. Sounds very easy, but beause I am new I decided to just test it out and get a sense of how it worked.<br><br>So I create an RRD:<br><br>rrdtool create hits.rrd --start 1141200000 --step 86400 DS:hits:GAUGE:172800:0:U RRA:MAX:0.5:1:3650<br><br>starting about 13 months ago, step size is one whole day ... I thought that ABSOLUTE was a better choice for a discrete number every day, but every example I saw of web hits people were using GAUGE, so I guess I will too.<br><br>Not sure if MAX is right, but the point is I do not want to do ANY averaging or summing or ANYTHING. I just want to plug in one number per day and graph that SINGLE number each day. The end. I assume MIN/MAX/LAST would provide the same results,
right ?<br><br>Ok, so the RRD creates without errors. Now I populate the first six days of data with make-believe values:<br><br>rrdtool update hits.rrd 1141286400:1 1141372800:10 1141459200:10 1141545600:12 1141632000:12 1141718400:12<br><br>Easy. Start time is 1141200000, so my first value will be +86400, and adding +86400 each value after that. Again, this completes without errors.<br><br>So, all is well - I'll just check the data with fetch to make sure it comes back just as I expect it to:<br><br># rrdtool fetch hits.rrd MAX --start 1141200000 --end 1141718400<br> hits<br><br>1141257600: 1.0000000000e+00<br>1141344000: 7.0000000000e+00<br>1141430400: 1.0000000000e+01<br>1141516800: 1.1333333333e+01<br>1141603200: 1.2000000000e+01<br>1141689600: 1.2000000000e+01<br>1141776000: nan<br><br><br>And
here are the problems. As you can see, the above output is completely wrong.<br><br>The first, obvious, and mind-blowing behavior is that the time values in the output DO NOT MATCH my data points. My first data point was at time:<br><br>1141286400<br><br>and fetch returns that data point at:<br><br>1141257600<br><br>And then, the obvious problem that the data values are not correct - the values I entered into the RRD are clearly:<br><br>1,10,10,12,12,12<br><br>and fetch is giving me back:<br><br>1,7,1,11.3,12,12<br><br>(the 11.3 is particularly humurous)<br><br>So, I give up. Is there a secret command line switch to "turn off the internal RNG that is applied to all dates and values" ?<br><br>My question is simple: How do I plug in 6 test values with 6 specific dates and successfully fetch them back out again _exactly as I entered them_ ?<br><br>Thanks.<br><p> 
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