Subject RE: [firebird-support] Running out of database!
Author Rick Debay
Seven servers times thirty connections in the pool equals two hundred
ten processes running on the server.
Process context switching is expensive, and if each process has a large
cache you're running out of memory.

Even with a "commercial" database, you can only load a database so much.
Normally you start pushing back by having connection limits in Tomcat,
and then higher limits in Apache, so that your 200 database connections
can handle one thousand concurrent Tomcat users and then five thousand
concurrent Apache users.

-----Original Message-----
[] On Behalf Of hay77772000
Sent: Tuesday, April 10, 2007 12:21 PM
Subject: [firebird-support] Running out of database!


We have a series of severs that are each running Tomcat, and load
balanced through Apache. They all share the same firebird database on a
dedicated machine on the backend - v1.5. We initially started with
SuperServer, but had stability and other problems with that, so we
switched to Classic. Each server uses a db connection pool with approx
30 connections.

When we scale up, we seem to hit a wall at around 7 servers, where the
database machine cannot keep up.

Can anyone suggest ways that we can get around this issue? Does anyone
have experience with some of the other "commercial" dbs - Oracle/Sql
Server etc.? Would switching to one of these likely help us?

many thanks,


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