Ok, so you have a large number of repetative queries that need to produce fast results on demand. Interesting that you stated "apparent" response time. That would imply that some fudging could take place.. but I won't go there.

My experience with this is in using Perl::DBI and MySQL. Because the answer you are passing back from the DB servers is basicly a single value, bandwidth should not be a problem. Holding the connection open (persistent) reduces time lag a great deal. The only time you would not do that is if you are pushing the number of allowed connections to your DB server(s).hmmmmm ...

You have busy DB servers so I would try to use persistent connections for the least amount of time. Maybe just make sure that you close each connection as soon as you get the second answer back from each server so that you are not hogging connections.

Percieved time delay is going to be database answer dependant... not network connection dependent... (IMO). You might also keep your fast query answers on the "answer" server(the one that calcs the averages) for as long as there is an open connection to you slowest server, not allowing any further connections to the fast servers until the slowest one responds, do the calcs, then close that last connection. That way you don't end up with a bunch of meaningless queries clogging up the network.

Hope this makes sense :-)

...the majority is always wrong, and always the last to know about it...

In reply to Re^3: Rapid inter-machine communication on internal network by wjw
in thread Rapid inter-machine communication on internal network by Anonymous Monk

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