Hi everyone,
I've asked for your help before and you've been very welcoming and
helpful, however now I have a few further issues.

I'm developing a highly concurrent middleware server app (C#) that
takes socket connections from a frontend webpage and performs
processing and SQL queries on a back end SQL server. I'm getting
massive improvements on my predecessor's efforts - I can sustain 1000
msgs/sec in some cases as opposed to a few tens before.

However, I'm hitting a point now where latency is creeping up (over a
minute under heavy load - which is unacceptable) and I think its down
to differing lengths of time it takes the incoming messages to execute
(some are very quick, a few are several seconds - credit card auth).

I'm using async sockets to read in and transmit responses, and the
built in threadpool and where possible the new async database
operations (in .NET 2.0 beta 2) to handle actual message processing, so
IO completion ports all over the place.

Ive been using a seperate threadpool class to place longer running
(over 1 sec) processing - but i'm unsure even after some testing as to
exactly what balance I should give and how many threads to allocate.
I'm assuming all 25 of the built in ThreadPool are a gimme, but how
many is reasonable to allocate seperately? I'm beginning to think
shifting all my processing to the seperate threadpool would be
beneficial too.

Any suggestions? I'm at a bit of a loss now, this is where my expertise
on the matter ends? I'd be eternally grateful if anyone could point me
in a useful direction!

Cheers,
Kieran