Cheshire Cat Computing

Hi there:
Brief confg: MRTG, RRDTool, Routers2.cgi

I'm getting the below error.
event log : Data collection did not complete within interval

For monitoring Windows I'm using WMI scripts, what I think is happening is that the WMI scripts (Are slow) are still running when MRTG next cycles through.

Will this effect the data collection, or will the rrd DB files still be updated but there will be a lag?

Thanks
Regards Jamie

I'm not completely sure, but it looks very much as you say - your data collection scripts are so slow that they are taking more than your (5 min?) polling window to run.

If MRTG does not complete its polling within the window, then the poll is missed, and 'unknown' is implicitly stored in the RRD for that window (if the poll subsequently completes, the data goes into the NEXT window in the RRD instead)

In the RRD is the 'XFF' setting which says how much of the data need to be there. This is default at 0.5 which means you can miss half the polls required for the RRA and get away with it, but miss more and it goes unknown.

The 'daily' graph is 1 poll per bucket, so miss one and you get a grey unknown.

The weekly is 6 polls per bucket, so as long as you have 4 of the 6 then it will still display.

And so on for monthly (24) and yearly (264).

Therefore, if you are missing half your polls (because a poll takes >5min to run), you'll get nothing.

You need to try to run more MRTG instances at once; under UNIX/Linux you can use Forks: to do this (doesnt work under Windows though) or split your cfg files into groups and run multiple instances of MRTG.

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

Thanks Steve. I'll run multiple instances of MRTG for now.

Not that impressed with the speed of WMI, very functional but slow