[rrd-users] can't sanity-check rrdtool with sample data ... please

--===============0922490123==
Content-Type: multipart/alternative; boundary="0-1889256284-1182893659=:49895"
Content-Transfer-Encoding: 8bit

--0-1889256284-1182893659=:49895
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

New user of rrdtool.

I plan on graphing the number of hits I get each day on my webserver.

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.

So I create an RRD:

rrdtool create hits.rrd --start 1141200000 --step 86400 DS:hits:GAUGE:172800:0:U RRA:MAX:0.5:1:3650

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.

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 ?

Ok, so the RRD creates without errors. Now I populate the first six days of data with make-believe values:

rrdtool update hits.rrd 1141286400:1 1141372800:10 1141459200:10 1141545600:12 1141632000:12 1141718400:12

Easy. Start time is 1141200000, so my first value will be +86400, and adding +86400 each value after that. Again, this completes without errors.

So, all is well - I'll just check the data with fetch to make sure it comes back just as I expect it to:

# rrdtool fetch hits.rrd MAX --start 1141200000 --end 1141718400
hits

1141257600: 1.0000000000e+00
1141344000: 7.0000000000e+00
1141430400: 1.0000000000e+01
1141516800: 1.1333333333e+01
1141603200: 1.2000000000e+01
1141689600: 1.2000000000e+01
1141776000: nan


And here are the problems. As you can see, the above output is completely wrong.

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:

1141286400

and fetch returns that data point at:

1141257600

And then, the obvious problem that the data values are not correct - the values I entered into the RRD are clearly:

1,10,10,12,12,12

and fetch is giving me back:

1,7,1,11.3,12,12

(the 11.3 is particularly humurous)

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" ?

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_ ?

Thanks.


---------------------------------
Choose the right car based on your needs. Check out Yahoo! Autos new Car Finder tool.
--0-1889256284-1182893659=:49895
Content-Type: text/html; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

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.&nbsp; 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.&nbsp; I just want to plug in one number per day and graph that SINGLE number each day.&nbsp; The end.&nbsp; I assume MIN/MAX/LAST would provide the same results,
right ?<br><br>Ok, so the RRD creates without errors.&nbsp; 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.&nbsp; Start time is 1141200000, so my first value will be +86400, and adding +86400 each value after that.&nbsp; 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>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&n bsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs p;&nbsp;&nbsp;&nbsp; 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.&nbsp; 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.&nbsp; 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.&nbsp; 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:&nbsp; 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>
<hr size=1>Choose the right car based on your needs.
Check out <a href="http://us.rd.yahoo.com/evt=48518/*http://autos.yahoo.com/carfinder/;_y...FyLWZpbmRlcg-- ">Yahoo! Autos new Car Finder tool.</a>

--0-1889256284-1182893659=:49895--


--===============0922490123==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
rrd-users mailing list
rrd-users@lists.oetiker.ch
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

--===============0922490123==--