[rrd-users] Strange values in RRA

[Olivier Nicole]

Replying to myself...

> I use RRD::Simple to add new DS in an RRD.
>
> I create the RRD with one DS:
>         <ds>
>                 <name> tick </name>
>                 <type> GAUGE </type>
>                 <minimal_heartbeat>600</minimal_heartbeat>
>                 <min>0.0000000000e+00</min>
>                 <max>NaN</max>
>
>                 <!-- PDP Status -->
>                 <last_ds>1</last_ds>
>                 <value>1.0000000000e+00</value>
>                 <unknown_sec> 0 </unknown_sec>
>         </ds>
> and very standards RRA:
>     'RRA:AVERAGE:0.5:1:600',
>     'RRA:AVERAGE:0.5:6:600',
>     'RRA:AVERAGE:0.5:24:600',
>     'RRA:AVERAGE:0.5:288:732'

Could my problem below (no values in RRA 2, 3 and 4) be linked to the
xff factor? I am observing scarce information, with one occurence
every day or less, so in each interval of 30, 120 or more minutes,
only one step will not be unknown: I need an xff of 287/288 ~ 0.9965
so my RRA should be:

     'RRA:AVERAGE:0.5:1:600',
     'RRA:AVERAGE:0.9:6:600',
     'RRA:AVERAGE:0.99:24:600',
     'RRA:AVERAGE:0.999:288:732'

Am I right?

Best regards,

Olivier


> At each step, I enter the value 1 for DS "tick".
>
> As time goes, I add new DSs.
>
> --------
>
> At 17:40 I add a new DS called "1":
>
>         <ds>
>                 <name> 1 </name>
>                 <type> GAUGE </type>
>                 <minimal_heartbeat>600</minimal_heartbeat>
>                 <min>0.0000000000e+00</min>
>                 <max>NaN</max>
>
>                 <!-- PDP Status -->
>                 <last_ds>U</last_ds>
>                 <value>NaN</value>
>                 <unknown_sec> 1 </unknown_sec>
>         </ds>
>
> and I enter the value 1 for DS "1"; in the first RRA, I get:
>
> <!-- 2012-11-22 17:40:00 ICT / 1353580800 -->
>     <row><v>1.0000000000e+00</v>
>          <v>9.9666666667e-01</v></row>
>
> --------
>
> At 19:25 I add a new DS called "2":
>
>         <ds>
>                 <name> 2 </name>
>                 <type> GAUGE </type>
>                 <minimal_heartbeat>600</minimal_heartbeat>
>                 <min>0.0000000000e+00</min>
>                 <max>NaN</max>
>
>                 <!-- PDP Status -->
>                 <last_ds>U</last_ds>
>                 <value>NaN</value>
>                 <unknown_sec> 1 </unknown_sec>
>         </ds>
>
> and I enter the value 1 for DS "1" and DS "2"; in the first RRA, I get:
>
> <!-- 2012-11-22 19:25:00 ICT / 1353587100 -->
>     <row><v>1.0000000000e+00</v>
>          <v>1.0000000000e+00</v>
>          <v>9.9666666667e-01</v></row>
>
> -------
>
> So far so good.There is no other data entry.
>
> But when I look at the second RRA, I get:
>
> <!-- 2012-11-22 19:30:00 ICT / 1353587400 -->
>     <row><v>1.0000000000e+00</v>
>          <v>NaN</v>
>          <v>1.9933333333e-01</v></row>
>
>
> While I would be expecting something along the line of:
>
> <!-- 2012-11-22 19:30:00 ICT / 1353587400 -->
>     <row><v>1.0000000000e+00</v>
>          <v>1.6666666666e-01</v>
>          <v>1.6666666666e-01</v></row>
>
> as there have been only one entry of value 1 in DS "1" and DS "2" in
> the past 6 steps.
>
> It could be an artefact of RRD::Simple that seems not to be working so
> well.
>
> Help appreciated,
>
> Best regards,
>
> Olivier
>
> _______________________________________________
> rrd-users mailing list
> rrd-users at lists.oetiker.ch
> https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users