[Fix Pack 1 or later]

JPA system properties

In addition to the settings that are accessible from the administrative console, you can set Java Persistence API (JPA) system properties using command-line scripting.

You can use the properties page to define the com.ibm.websphere.jpa.entitymanager.poolcapacity JPA system property. Add the system property directly to the server.xml file or as a generic Java virtual machine (JVM) argument using the administrative console.

com.ibm.websphere.jpa.entitymanager.poolcapacity

Use this property to specify the default pool capacity for all JPA EntityManager instances on a server.

Data type Integer
Range 0 to 500
Default 10

There is a separate pool of EntityManager instances for every persistence context reference that is defined in an application. A persistence context reference can be @PersistenceContext or a persistence-context XML element.

This property setting affects all pools in the application server process. Each pool uses the capacity defined by this property. Although the JPA specification supports pooling of EntityManager instances, some JPA providers might not support the pooling. By default, pooling of EntityManager instances is only enabled for the JPA providers supplied with WebSphere® Application Server. The default pool capacity is 10.

When this property is enabled, EntityManager pooling is enabled for all JPA providers. If a JPA provider stops functioning normally when this property is enabled, disable the property and contact the JPA provider for support.

Increasing the integer value of this setting might improve performance by reducing the number of EntityManager instances that must be created. However, increasing the value affects the amount of consumed memory.




Related tasks
Configuring OpenJPA caching to improve performance
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Last updatedLast updated: Sep 19, 2011 7:16:32 PM CDT
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