Cheshire Cat Computing

I am a new router2.cgi user.
After I installed the router2.cgi, I found the value on “current in/out” field at the bottom of graphs always display on “zero”, but the max and avg fields displayed the correct values. I don’t know where is wrong. Could you please help me on this?

I also did some tests by using the rrdtool graph commands to create graphs. For these graphs, the current in/out value is able to display. Therefore,that means the rrdtool store the last updated data correctly but it can’t be gathered by router2 script for some reasons.

Many thanks.

This is a known problem caused by a race condition in MRTG.

If a graph is built from multiple RRD files, which update at different times, you will get a period of between 0s and 5min during which the 'current' value for some of the components will be zero. The 'current' value is not the same as the 'last' value!

EG, if you update at 12:04:59, right at the end of the 5min window, then between 12:00 and 12:04:58, then 'current' value is unknown (the 'last' value is the one you submitted some time between 11:55:00 and 11:59:59).

Routers2 tries to work around this but cannot always do so, particularly when several different RRD files are being combined into a graph.

Another workaround is to have 'uselastupdate = yes' in your Routers2.conf which bases graphs on the last update time, not on the current time.

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