#1158 new enhancement

make SNMP multigraphs look like MRTG graphs

Reported by: anarcat Owned by: nobody
Priority: normal Milestone: Munin 2.0.0
Component: plugins Version: 1.4.6
Severity: normal Keywords: mrtg pola patch


Here at Koumbit we have done a patch to make the SNMP multigraphs look like MRTG graphs. There are multiple reasons for this:

  1. POLA (Principle of Least Astonishment) - most graphing software does it that way and it's confusing to switch to Munin and try to figure it out from there
  2. Comparing graphs is easier - with the current graphs, comparing the graph from both ends of a cross-connect in switches si very hard as the graphs are reversed, and simply can't be compared without being either very good with visuals or using graphical software.

I have attached graph examples of two interfaces that are supposed to match, to give an idea of the latter problem.

I have also attached a patch which makes the received graph be a green AREA and sent graph be a blue LINE1, both on the positive side. I think it covers most of the transition.

I know this is a sensitive and highly debatable issue. I am also aware there is a workaround proposed in the FAQ. However this workaround assumes that I create a snippet for every single port for every switch we monitor, which currently means around 300 code snippets - basically defeating the whole idea behind the SNMP multigraph plugin.

I would go as far as saying that the default if_ graphs should also be changed so they can be compared with the SNMP graphs, but I am not sure I can win that fight, so I write provide a patch only if there is some sympathy with it. ;)

Attachments (5)

if_50-day-before.png (24.2 KB) - added by anarcat at 2011-10-28T20:07:15+02:00.
interface 50, before change
if_1-day-before.png (23.9 KB) - added by anarcat at 2011-10-28T20:07:49+02:00.
interface 1, before change
if_50-day-after.png (20.9 KB) - added by anarcat at 2011-10-28T20:16:33+02:00.
if_1-day-after.png (20.5 KB) - added by anarcat at 2011-10-28T20:16:48+02:00.
munin_mrtg_graphs.patch (4.0 KB) - added by anarcat at 2011-10-28T20:18:03+02:00.

Download all attachments as: .zip

Change History (6)

Changed at 2011-10-28T20:07:15+02:00 by anarcat

interface 50, before change

Changed at 2011-10-28T20:07:49+02:00 by anarcat

interface 1, before change

Changed at 2011-10-28T20:16:33+02:00 by anarcat

Changed at 2011-10-28T20:16:48+02:00 by anarcat

Changed at 2011-10-28T20:18:03+02:00 by anarcat

comment:1 Changed at 2012-03-05T10:04:24+01:00 by kenyon

  • Keywords patch added

You make a good argument for the MRTG style, but there are so many plugins, both in the main distribution and in the contrib repository, that use the negative-positive style. In addition to if_, I know of netstat_multi, ip_, diskstats, swap, and tor_bandwidth_usage. It seems that some of these would not be very readable in MRTG style. Personally, I find it pretty easy to see that the switch cross-connect interface graphs match in shape and in numbers, with the current munin style.

Maybe you should post a message to the munin-users mailing list to get opinions on this. Otherwise, I'm afraid we might have to close this without applying the patch, because the munin negative-positive style seems pretty well entrenched into so many munin plugins.

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