Cheshire Cat Computing

hy steve,

i tried to do the following:

i have 2 lan interfaces for which i get the in/out bps.
what i wanted to have is a range-graph of both input values ranged and a second graph with both output-values ranged.

now i tried the following:
routers.cgi*Graph[INT-A]: combined-out noi #00FF00
routers.cgi*Graph[INT-A]: combined-in noo #00FF00
routers.cgi*Graph[INT-B]: combined-out noi #0000FF
routers.cgi*Graph[INT-B]: combined-in noo #0000FF

routers.cgi*InCompact[_combined-out]: no
routers.cgi*InSummary[_combined-out]: yes
routers.cgi*Options[_combined-out]: nomax nototal
routers.cgi*GraphStyle_combined-out]: range

routers.cgi*InCompact[_combined-in]: no
routers.cgi*InSummary[_combined-in]: yes
routers.cgi*Options[_combined-in]: nomax nototal
routers.cgi*GraphStyle_combined-in]: range



...

but as i expected this doesnt work, as routers.cgi cals the range between the in/out values of each device.

how could i achieve what i want? a range between the in-interfaces of 2 devices / the out-interfaces of 2 devices?


one alternative of course would propably be the gather the real in-value of one device as a mrtg-in of a virtual device and the real in-value of the other device as mrtg-out of a virtuel device.
but his would mean i have to double-poll a device, which i would prefer the prevent.


maybe this could lead to a new feature proposal for the next version :-)

another nice thing would be to have mrtg calc the differene betwen 2 in values of a device and show that as graph :-)

So.. you want to create a range graph, where the upper limit is the 'in' from one target, and the lower limit the 'in' from another?

Sorry, can't be done (yet).

The 'range' graph style is a special one, and graphs (as a floating bar) the range between the 'in' and 'out' values for a single Target. I haven't tried this in a userdefined, but I suspect it looks highly wierd if it displays anything at all, since it will be looking at the wrong values and they may well cross.

The only thing you can do, really, is to have a standard line graph, and fill in the gap between the two lines mentally.

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

yes, that works, but the problem is the scale:

if the interfaces have 50 and 55 mbit/s peak load, you will hardly see the 5mbit/s.
especially when the lower rates are near 0.

background:
i want to measure the internet traffic which is saved by the internet cache :-)
so i measure the lan-port of the cache device and the serial port of the internet router.

How about using the power of MRTG to do this?

For example, just define a new Target

Target[cachesaving]: #7/24:public@yyy:::::2 - #3/34:public@yyy:::::2
MaxBytes[cachesaving]: (insert the bandwidth of your link here)
routers.cgi*Options[cachesaving]: scaled
Legend1[cachesaving]: Saved incoming bytes
Legend2[cachesaving]: Saved outgoing bytes

This would probably achieve what you want, although at the expense of a couple of extra SNMP lookups and an extra .rrd file.

Steve

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11