Thread pools
Inside the application server JVM separate thread pools are used to managed
different types of workload. Depending on your type of application appropriate
thread pools require careful planning. Some of them are,
1. Web Container thread pool
2. EJB container thread pool
Database connection pool
The database connection pool is another common location for bottlenecks,
especially in data-driven applications. The default pool size is 10, and depending on the nature of the application and the number of requests, the default setting might not be sufficient. During implementation testing, pay special attention to the pool usage and adjust the pool size accordingly. The connections in the pool consume additional Java heap, so you might be required to go back and adjust the heap size after tuning the pool size. Be aware that in a clustered environment, the connection pool is a cell resource. This means that all nodes in the cluster share one pool. Adjust the pool in such way that it is large enough to handle the requests of all the servers participating in the cluster and cell.
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Posted By: Morgan at Jul 9 2009 4:25AM