Plugin selinux_avcstat can give floating point output instead of integers

[wferi]

If a sum is high enough, AWK switches to exponental notation, which Munin rightfully interprets as floating point quantity and thus to accept as a DERIVE reading for (although it's documented, it doesn't make much sense in my opinion). Anyway, I recommend the attached patch, which gets rid of AWK in this plugin.

[wferi]

There may be other problems with the plugin as well:

1. It mentions lookups twice in graph_order, is this actually supported?

   echo 'graph_order lookups hits misses allocations reclaims frees lookups'
   

2. lookups = hits + misses, so it doesn't make much sense to draw them stacked anyway.

[jo]

Patch applied, and graph_order fixed, for the 1.4 branch and trunk (r4109, r4110).

Thanks. :)

[wferi]

Thanks, this is certainly a step forward.

However, lookups = hits + misses (modulo counter wraps), so there really isn't any point in stacking all three. In my opinion, lookups shouldn't be graphed at all, but hits should be stacked over misses, and that's it. The other three fields (allocations, reclaims and frees) are pretty much independent, thus should be graphed as simple lines (there's no point in stacking them). Also, all other quantities are usually dwarfed by hits, so plotting them against a single axis won't make for particularly good graphs...

[jo]

Sorry, missed that bit. :-)

I don't use this plugin myself, so not sure how it looks. What would make most sense?

1) remove lookups completely
2) graph lookups as a line (not stacked) as an overlay on the stacked data

[wferi]

I'd say: stack hits over misses, drop lookups completely (that would only add a contour to the former stack) and finally graph all the rest as simple lines (not stacked).

I feel like adding Lars Strand lars (at) gnist org, the original author to the Cc: list would be a good move beforehand, in case I misunderstood something. I'm not a selinux expert myself.