Re: [gentoo-user] strange TCP timeout errors

[Grant <emailgrant@gmail.com>]

> It's as I thought - your data is accurate but rrd has been given a
> completely wrong method to derive the graphs.
>
> Munin graphs for section "Network" do not have to be in a file called
> "network" - it's just a category and the plugin defines what web-page
> section it must be in. In your case, the relevant plugin is
> netstat_multi which doesn't often get installed. It's data source is
> "netstat -s" so grep that output for "timeout" to see it.
>
> Timeouts are cumulative counters, they do not get less till they wrap
> around. So to scale them, the plugin gets the rrd file to subtract
> previous reading from current reading and divide by the time interval to
> get the timeouts/sec. This is all done inside rrd when the data files
> are updated (it's quite a lot of magic)
>
> That plugin sets the graph type to DERIVE
> (/etc/munin/plugins/netstat_multi around line 190. I feel it should be
> GAUGE or COUNTER.
>
> The proper reference on rrd is
> http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html
> and the munin docs are
> https://munin.readthedocs.org/en/latest/index.html
>
> You must edit the plugin file and IIRC recreate the rrd, you will lose
> all past info (can't be helped).
>
>
> [snip ls output]
>
>
>> P.S. Any other good plugins you'd recommend?
>
> http://gallery.munin-monitoring.org/
>
> Monitoring is highly site-specific so recommendations aren't usually
> worth much, but that gallery has LOTS of contributed plugins


Many thanks Alan!

- Grant