Load-balancing Database Connection Pool

What database conn开发者_C百科ection pool could be used to load-balance connections from a Tomcat web container to one of several Oracle database servers without using RAC clustering?

I'm assuming these are read-only databases or you're not concerned connections will get different data. If you want the data to be the same, you can use streams replication which is doesn't require RAC.

The connection load balancing and failover happens in the listener. There's a lot of flexibility in how this works and this should get you started:

http://download.oracle.com/docs/cd/E11882_01/network.112/e10836/advcfg.htm#sthref858

The first part shows a simple client based load balance which is essentially picking a connection at random. Farther down it shows how to load balance based on actual server load.

Look into DRCP if using 11g