[Xymon] monitoring aggregated network traffic

[Martin Flemming]

On Sun, 30 Oct 2011, netz-haut - stephan seitz wrote:

> Hi,
> 
> thanks for your very helpful answer.
> It took me a few days to get back to that issue, so sorry for that late responose.
> 
> I've added additional lines for outgoing, and it works as expected.
> 
> I'm absolutely fine with hardcoed interfaces, cause I need the aggregated view of
> particular interfaces.
> 
> 
> Thanks again,
> 
> Stephan
> 
> 
> 
> 
> Am Donnerstag, den 13.10.2011, 19:42 +0200 schrieb Henrik Størner:
> 
> 
> On 13-10-2011 16:44, netz-haut - stephan seitz wrote:
> 
> > is there any "usual" way, to monitor and graph the traffic of a bulk
> > of network interfaces? The reason is, some of our hosts are connected
> > to iSCSI storages via multipath over two or four independent
> > interfaces. Since the traffic is balanced equally, every interface
> > shows (more or less) the same amount of traffic. This leads to very
> > useless rrdtool graphics as there is only one multicolored thick line
> > visible. It would be really helpful to see a graph which shows the
> > SUM of the particular interfaces.
> 
> This can be done by creating an RRD graph definition to do the summation
> for you.
> 
> In RRDtool, you first use one or more "DEF" lines to grab specific data
> items from one or more RRD files, and put them into some "variables".
> You can then either use these variables directly to make a line on the
> graph, or you can use them for calculating other variables via a "CDEF"
> line.
> 
> The default ifstat graph has these lines:
>
>          DEF:inbytes at RRDIDX@=@RRDFN@:bytesReceived:AVERAGE
>          CDEF:in at RRDIDX@=inbytes at RRDIDX@,8,*
> 
> (The @RRDIDX@ and @RRDFN@ are because this graph repeats over all the
> interfaces - Xymon replaces these with a number and the RRD filename).
> 
> What this does is to first define a variable "inbytes at RRDIDX@" which has
> the "bytesReceived" value from the RRD. The it computes another
> variable, "in at RRDIDX@" as 8*inbytes - to convert from bytes to bits.
> The notation here is Reverse Polish (RPN).
> 
> So if you have 4 RRD files, one for each interface, you can have RRDtool
> do the math for you like this:
> 
> [ifsum]
>          TITLE Network Traffic
>          YAXIS Bits/second
>          DEF:inbytes0=ifstat.eth0.rrd:bytesReceived:AVERAGE
>          DEF:inbytes1=ifstat.eth1.rrd:bytesReceived:AVERAGE
>          DEF:inbytes2=ifstat.eth2.rrd:bytesReceived:AVERAGE
>          DEF:inbytes3=ifstat.eth3.rrd:bytesReceived:AVERAGE
>          CDEF:intotal=inbytes0,inbytes1,inbytes2,inbytes3,+,+,+
>      CDEF:inbits=intotal,8,*
>      LINE:inbits#FF0000:Aggregate inbound
> 
> The "LINE" definition then uses the "inbits" value to draw a (red) line
> with this data.
> 
> Have a look at graphs.cfg, and I'm sure you can figure out to add a line
> for the outgoing data also.
> 
> Add "ifsum" to the GRAPHS setting in xymonserver.cfg, and the graph
> should show up on the "trends" page.
> 
> 
> Regards,
> Henrik
> 
> PS: I haven't actually tested any of this, so feel free to provide
> corrections :-)

Hi !

I knew, this thread is very old,
but i want this feature very much :)

..  unfortunately something is missing in my enviroment,
because i couldn't see the ifsum-graph on the trend-page ... :-(

Can somebody give me an advice how i debug this missing graph ?

My xmon-server is running the 4.3.7-version ..

thanks & cheers,

        Martin