Subj : threaded application scalability question
To   : comp.programming.threads
From : Luke  Ehresman
Date : Wed Feb 16 2005 08:05 am

This is related to a question I posted earlier today regarding a
threaded application I am writing, but thought this would be best
suited for a different thread.

I am writing an application that accepts socket connections and also
maintains a session for a user across multiple connections.  I would
like to be able to do processing on that session when the user is not
connected.

Currently I have a pool of threads to handle connections, and they
attach to global sessions.  The locking required to maintain the
sessions is quite complex (because I also have other threads
manipulating the session data).

My question:  Would it be reasonable to create a thread when a new
session is created (i.e. a new user logs in), and have that thread stay
active as long as the user is logged in.  This thread would have a
session in its local context, and would do processing on that session
when the user isn't connected.  There would be no global session
structures.  When the user reconnects, he would get attached to the
existing thread for that session, and that thread would handle his
connection again.

Would this be a scalable solution?  In my application, I could
potentially have hundreds of users logged into the system at one time.
What are the implications of having hundreds of threads active?

I would probably still have a pool of threads already created, but
rather than handling individual connections, they would handle sessions
(i.e. they would be occupied and not in the pool for as long as the
user is logged into the system, not just when they're connected to the
server).

Thanks,
Luke

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