Re: [Quickfix-developers] Newbie: Session management in load balanced situation?

[Caleb E. <cal...@gm...>]

On Tue, 8 Mar 2005 12:57:38 -0600, David Kuik <dav...@pr...> wrote:

> I'm wondering how the engine manages sessions and message sequencing in a
> load balanced environment.  Does each server in the farm to manage a
> separate session or do they somehow share a session? 
> 
> I'm trying to understand how this will work in a fault-tolerant 7x24
> environment that supports 1000's of users.  Can someone offer some comments?

You could load balance sessions across multiple machines using a
database-backed message store (e.g. MysqlStoreFactory).  All of the
session state is persisted to the database.  You could run a number of
Acceptors in parallel on different machines, each configured to accept
all of your MySQL-backed sessions (e.g. same config file).

However I don't think there is currently a facility in QF for
"locking" a session across multiple engines.  In other words, if
client A connects to server 1, that session should be "locked" in some
way so any attempt to use it on servers 2 through n would result in an
error in the same way that connecting to that session a second time on
server 1 would.

A similar approach would be to use the FileStoreFactory and share all
the session state on an NFS mounted filesystem.

-- 
Caleb Epstein
caleb dot epstein at gmail dot com