Sun Microsystems 820434310 manual Connector Connection Pool Settings, Transaction Support

Connection Validation Required

Connection	If true, the pool validates connections (checks to find out if they are usable) before providing them to an
Validation	application.
Required
	If possible, keep the default value, false. Requiring connection validation forces the server to apply the
	validation algorithm every time the pool returns a connection, which adds overhead to the latency of
	getConnection(). If the database connectivity is reliable, you can omit validation.

Validation Method Type of connection validation to perform. Must be one of:

■auto-commit: attempt to perform an auto-commit on the connection.

■metadata: attempt to get metadata from the connection.

■table (performing a query on a specified table). Must also set Table Name. You may have to use this method if the JDBC driver caches calls to setAutoCommit() and getMetaData().

Table Name	Table name to query when Validation Method is “table.”
Close All	Whether to close all connections in the pool if a single validation check fails. The default is false. One
Connections On	attempt will be made to re-establish failed connections.
Any Failure

Connector Connection Pool Settings

From a performance standpoint, connector connection pools are similar to JDBC connection pools. Follow all the recommendations in the previous section, “Tuning JDBC Connection Pools” on page 77

Transaction Support

You may be able to improve performance by overriding the default transaction support specified for each connector connection pool.

For example, consider a case where an Enterprise Information System (EIS) has a connection factory that supports local transactions with better performance than global transactions. If a resource from this EIS needs to be mixed with a resource coming from another resource manager, the default behavior forces the use of XA transactions, leading to lower performance. However, by changing the EIS’s connector connection pool to use LocalTransaction transaction support and leveraging the Last Agent Optimization feature previously described, you could leverage the better-performing EIS LocalTransaction implementation. For more information on LAO, see “Configure JDBC Resources as One-Phase Commit Resources” on page 39

In the Admin Console, specify transaction support when you create a new connector connection pool, and when you edit a connector connection pool at Resources > Connectors > Connector Connection Pools.

Also set transaction support using asadmin. For example, the following asadmin command could be used to create a connector connection pool “TESTPOOL” with the transaction-support as “LOCAL”.

80 Sun GlassFish Enterprise Server 2.1 Performance Tuning Guide • January 2009