On Tuesday 10 March 2009 11:53:12 Iain M Conochie wrote:
Good morning Xymonners!
I have an issue I was hoping someone could help me with. I have
created an NCV definition for a mysql script to graphs slow queries and
also queries per second. The definition is here:
[mysql]
TITLE MySQL Queries
YAXIS Amount
DEF:questions=mysql.rrd:questions:AVERAGE
DEF:slow=mysql.rrd:slowqueries:AVERAGE
LINE2:questions#0000FF:Queries
GPRINT:questions:LAST: \: %5.1lf (cur)
GPRINT:questions:MAX: \: %5.1lf (max)
GPRINT:questions:MIN: \: %5.1lf (min)
GPRINT:questions:AVERAGE: \: %5.1lf (avg)\n
LINE2:slow#00FF00:Slow Queries
GPRINT:slow:LAST: \: %5.1lf (cur)
GPRINT:slow:MAX: \: %5.1lf (max)
GPRINT:slow:MIN: \: %5.1lf (min)
GPRINT:slow:AVERAGE: \: %5.1lf (avg)\n
This is all well and good. Here is a shortened output of the script:
threads: 4
questions: 681188
slow queries: 2
Now Questions is ALWAYS increasing; so i felt that the average statement
would be the correct one. However, if i restart the mysql service or even
the box and Questions drops to 0 then bad things happen to the graphs. The
spike downwards to large negative numbers. Now rrd is doing what it should
be doing i.e. giving me an average of the range of numbers. Is there
another definition I can use to not have this effect?
This is determined by the actual DS definition the RRD tool library uses,
which for the NCV collector is set by the NCV_<testname> environment variable,
which is typically set in hobbitserver.cfg. Show us what you have for
NCV_mysql in hobbitserver.cfg, and please read the sections on DERIVE and
COUNTER in the rrdcreate man page.
Regards,
Buchan