Munin Graph - How To Set Max Upper Limit For mysql slowqueries & munin stats?

Question

Wow, this is my very first post on stackoverflow! Been using results for years, but this is the first time I'm 100% stumped and decided to join!

I use Munin to monitor and graph stuff like CPU, Memory, Loads, etc. on my VPS.

Sometimes I get a huge statistical outlier data point that throws my graphs out of whack. I want to set the upper limit for these graphs to simply avoid having these outliers impact the rest of the data view.

After hours of digging and experimenting I was able to change the upper limit on Loads by doing the following:

cd /etc/munin/plugins
pico load

I changed: echo 'graph_args --base 1000 -l 0'

to: echo 'graph_args --base 1000 -l 0 -u 5 --rigid'

It worked perfectly!

Unfortunately I've tried everything to get munin stats processing time and mysql slowqueries to have an upper limit and can't figure it out!

Here is the line in mysql_slowqueries

echo 'graph_args --base 1000 -l 0'

... and for munin_stats

"graph_args --base 1000 -l 0\n",

I've tried every combo of -u and --upper-limit for both of those and nothing I do is impacting the display of the graph to show a max upper limit.

Any ideas on what I need to change those lines to so I can get a fixed upper limit max?

Thanks!

Answer 1

I highly encourage playing with the scripts, even though you run the risk of them being overwritten by an update. Just back them up and replace them if you think it's needed. If you have built or improved things, don't forget to share them with us on github: https://github.com/munin-monitoring/munin

When you set --upper-limit to 100 and your value is 110, your graph will run to 110. If you add --rigid, your graph scale will stay at 100, and the line will be clipped, which is what you wanted in this case.

Your mysql_slowqueries graph line should read something like (it puts a limit on 100):

echo 'graph_args --base 1000 -l 0 --upper-limit 100 --rigid'

Answer 2

Changing the scripts ist highly discouraged since with the next update they might be replaced by the package manager and ando your changes.

Munin gives you different ways to define limits on the settings. One the node itself as well as on the server.

You can find (sort of) an answer in the FAQ.

For me it worked really nicely to just create a file named /etc/munin/plugin-conf.d/load.conf with the following content:

[load]
    env.load_warning 5
    env.load_critical 10

Restart munin-node to apply the changes and on the next update of the graph you can see theat the "warning" and "critical" levels have been set by clocking on the load-graph in the overview (table below the graphs)