[collectd] MySQL plugin reports wrong numbers on mysqld restart

Bostjan Skufca bostjan at a2o.si
Wed Sep 29 03:09:28 CEST 2010

Maybe it's time to make a script for automated dump/change obviously
invalid data to NaN/import of rrds.

Anyway, it is indeed COUNTER in my RRD files.
Do you know how  why it was not DERIVE specified at rrd creation?

Probably I should consult google and manuals for this, but: is there
an easy way to change from COUNTER to DERIVE or do I have to dump and
reload the data?


On 27 September 2010 14:27, matthew sporleder <msporleder at gmail.com> wrote:
> On Mon, Sep 27, 2010 at 7:44 AM, Bostjan Skufca <bostjan at a2o.si> wrote:
>> Hi all!
>> Has anyone else noticed that MySQL plugin reports wrong numbers when
>> mysql is restarted and collectd is not?
>> It seems like it takes absolute value of i.e. queries per second (0
>> when mysql is restarted minus i.e. 8 million just before restart) and
>> calculates abs(- 8 million) = 8Mqps.
>> If I restart MySQL every 2 months there is nothing I can see on the
>> graphs because those restart spikes are so high that everything else
>> is depressed down to zero.
>> Does anyone have a fix/suggestion of fix for this?
> What is the data type being used by the graphs?  It could be a COUNTER
> vs DERIVE situation to handle the reset.
> For your current graphs try adding a -u (upper limit).
> Or you might also be able to find a way to kill those bad values from
> the actual db if you take some backups first.  :)

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