[rrd-users] Average problem

[Gwenael Lahay]

Hello,

I store network flows in various rrd file.

I use this options to create rrd files :
rrdtool create test.rrd --step 60 DS:bytes:ABSOLUTE:400:0:U
DS:packets:ABSOLUTE:400:0:U DS:flows:ABSOLUTE:400:0:U RRA:AVERAGE:1:0:4320
RRA:AVERAGE:0:5:2016 RRA:AVERAGE:0:15:2976

I create a rrd when i found a flow.

I have a problem on average calculation.

For example, i detect a flow at 2007-11-14 10:30:00. Then i create a file
with the first value at this timestamp.
Then, i have only zero value.

...
<!-- 2007-11-14 10:28:00 CET / 1195032480 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
<!-- 2007-11-14 10:29:00 CET / 1195032540 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
<!-- 2007-11-14 10:30:00 CET / 1195032600 --> <row><v> 1.5000000000e+00</v><v>
1.6666666667e-02 </v><v> 1.6666666667e-02 </v></row>
<!-- 2007-11-14 10:31:00 CET / 1195032660 --> <row><v> 0.0000000000e+00</v><v>
0.0000000000e+00 </v><v> 0.0000000000e+00 </v></row>
<!-- 2007-11-14 10:32:00 CET / 1195032720 --> <row><v> 0.0000000000e+00</v><v>
0.0000000000e+00 </v><v> 0.0000000000e+00 </v></row>
...

The problem is that the average which is calculated every half an hour
indicates NaN at 10:30:00 while i am waiting from a value greater than zero.

 <!-- 2007-11-14 09:00:00 CET / 1195027200 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
<!-- 2007-11-14 09:30:00 CET / 1195029000 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
<!-- 2007-11-14 10:00:00 CET / 1195030800 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
 <!-- 2007-11-14 10:30:00 CET / 1195032600 --> <row><v> NaN </v><v> NaN
</v><v> NaN </v></row>
<!-- 2007-11-14 11:00:00 CET / 1195034400 --> <row><v> 0.0000000000e+00</v><v>
0.0000000000e+00 </v><v> 0.0000000000e+00 </v></row>
<!-- 2007-11-14 11:30:00 CET / 1195036200 --> <row><v> 0.0000000000e+00</v><v>
0.0000000000e+00 </v><v> 0.0000000000e+00 </v></row>

Could you help me ? Is there a solution to initialize the rdd with zero
values ?

Thanks

Sorry for my bad english
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