WAS v8.5 > Reference

JPA system properties

In addition to the settings that are accessible from the dmgr console, we can set JPA system properties using command-line scripting.

We can use the properties page to define the com.ibm.websphere.jpa.entitymanager.poolcapacity JPA system property. Add the system property directly to server.xml or as a generic JVM argument using the dmgr console.


com.ibm.websphere.jpa.entitymanager.poolcapacity

Specify the default pool capacity for all JPA EntityManager instances on a server.
Information Value
Data type Integer
Range 0 to 500
Default 10

There is a separate pool of EntityManager instances for every persistence context reference 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


Configure OpenJPA caching to improve performance


+

Search Tips   |   Advanced Search