It's the thread ID where the particular console line originates.

I've read that this will turn it off: 

DEBUG_THREADID=0

but it can always be useful for troubleshooting down the line. I've had to use it to tie agent messages back to traces.

G'Day MT

To quote a scotsman -> "your a bloody legend" 

The beers are on me at the pub this friday :)

NG