Munin again, sorry!

Okay this might start to be boring, but I’m still working on Munin, and that means you have to read (or not) another post on the topic.

So last time I was talking about Munin and I was intending to write about SNMP, but with one thing and another I ended up just writing about IPMI.

The only thing I want to put in clear now about SNMP is that I’m still working on it — the main issue seems to be that the Munin plugins have a default timeout of 10 seconds, but the multigraph plugin that should be used for mapping multiple SNMP interface takes about 24 seconds for the switch I’d like to monitor here at my workplace. This should technically be solvable by using the new async daemon support, but this requires, in turn, support for the SSH transport, which can’t be used without relaxing the security applied to munin user (by making it loggable). There is also another point I have to make: I intend to modify the plugin and make a second one that actually allows to graph all the interfaces on one single entry, so that it actually allows me for more interesting data.

For what concerns IPMI instead: the new version of Munin 2 in Gentoo replaces both the IPMI plugins (ipmi_ and ipmi_sensor_) with my version based off FreeIPMI, which now not only outperforms the original ones (thanks to FreeIPMI caching, which is enabled by default), but also outfeatures the original plugins! Here’s the gist of it:

• by using FreeIPMI, the plugin is shorter, much shorter, as the output is malleable to script handling;
• I’ve made the script accept both the names used by ipmi_ and ipmi_sensor_ — both reported the same data, but one used bash and gawk (the GNU version only), while the other used python;
• thanks to Kent I was able to get enough data to make it report power and current as well as temperatures and fans; I still have to implement voltage that was not implemented in the previous plugins either;
• thanks to Albert, the new 1.2 series of FreeIPMI has support for threshold output — which was the remaining missing feature; I’ve implemented it in the plugin and I’ve patched 1.1.6 (and 1.1.7) to support the option as well;
• and since I cared … the new version uses POSIX-compatible sh syntax and POSIX awk syntax instead of the GNU variants of both.

My next development is going to be supporting what they call “foreign hosts” on the plugin, so you can actually get Munin to monitor an IPMI SBMC instead of the local BMC interface. This will probably come soonish in Gentoo together with the support for asyncd.

What remains now is finding a way to package the contributed plugins which needs to be available, especially since Steve said he doesn’t want new plugins in the main package, and everything else has to come through the new contrib repository.

And yes, I still have to fix HTML generations, Justin, I know. I’m trying to find what the heck is wrong with it.