I am writing a custom munin plugin/graph and it's slightly computationally expensive. It's also unlikely to change much in a few minutes. Is it possible to have this one graph/plugin only update once per hour, and leave the rest of my graphs to update at the usual once per 5 minutes?
I had a similar problem and had the real plugin in cron writing the data every hour to a temp file and then a reading plugin that ran every 5 minutes from munin, but only displayed the last line from the temp file.
A better way to do it is to change your munin so that graphs are generated on demand, not every five minutes.
This page appears to have an overview: http://waste.mandragor.org/munin_tutorial/munin.html#cgi
I had the same problem running munin on my Raspberry Pi. Since the Raspberry Pi is not that powerful it was having a lot of keeping up with the five intervals set up by Munin.
Edit the file /etc/cron.d/munin, add the following line:
The file /usr/bin/munin-graph does not exist yet, so we are going to create it:
Now add this:
and make it executable:
Now edit the /usr/bin/munin-cron file and comment out the lines we put in the munin-graph file:
By doing this, the munin-update runs every 5 minutes, and the graphing and HTML page creation runs only once per hour (2 minutes after the full hour).