I have defined an additional graph (in Munin, munin.conf
) that calculates the total size of my MySQL database. The index and data sizes are extracted from an external plugin. The definition looks like this:
[...]
[Database;my.host.com]
address my.host.com
use_node_name yes
dbsize.update no
dbsize.graph_args --base 1024 -l 0
dbsize.graph_title Total database size
dbsize.graph_vlabel bytes
dbsize.graph_category mysql
dbsize.graph_info The total database size.
dbsize.graph_order the_sum
dbsize.the_sum.sum \
my.host.com:mysql_size.index \
my.host.com:mysql_size.datas
dbsize.the_sum.label data+index
dbsize.the_sum.type GAUGE
dbsize.the_sum.min 0
[...]
Now, is it possible to extract the current value of this graph? Running
# munin-run dbsize
or
# munin-run my.host.com:dbsize
does not seem to work.
Maybe you could try getting the value directly from RRDTool?
Munin mantains rrdtool (.rrd) files for the sources, you could try using rrdtool directly on munin's rrd to get the values.