Sockets question -- MIDRANGE-L

I have used Scott Klement's Socket programs for years. I have recently
started at a new
company and am once again using these programs (and the "Socket
Tutorial" Scott wrote).

I have implemented a system that has a central connection program which
spawns jobs.
In testing at present, we get an average 5 - 6 spawned jobs (this is a
POS interface
and will have about 30 - 40 POS centres accessing the iSeries at
go-live).

I don't think I have a problem with the sockets as such, they are
working fine, doing
what they are supposed to and returning requested data. Socket server
instances (the
spawned jobs) are all sitting on a "RcvDtaQ", waiting for a request to
hit it, then
process it. I have proper processes in place to handle multiple
requests coming in
so I don't lose any.

Sockets are open and always stay open (I am working on finding a way to
close them after a
period of inactivity, but that is not my problem, I think). What does
happen is that all of
a sudden, after working perfectly for a period of time, the server
instances (all of them)
will no longer respond. A debug on the program shows nothing hitting
the dataqueue hence no
responses ... But data is sent from the POS station (we have a
simultaneous trace on it).

One minute it works, the next it doesn't. Stop SBS and start SBS, and
all is fine again.
Could be 24 hours, could be 10 minutes and I have to do it again. This
will not be acceptable
in a live environment of course.

I cannot find anything (tutorials, google or otherwise) that even hints
at this sort of
problem. I want to believe it may be as simple as a TCP/IP setting ...
somewhere.

Has anyone had anything similar (and I should brush up on my search
words)? Is this a known
problem? Is there anything else I can tell you that may help? I am NOT
a TCP/IP expert, I
know a little, enough to be dangerous.

Any help is much appreciated.

Rick

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