The ha persistence type uses the high-availability database (HADB) for session persistence. The HADB must be installed and the enterprise profile must be selected. For information about profiles, see Usage Profiles in Sun Java System Application Server 9.1 Administration Guide.
The HADB allows sessions to be distributed. For details, see Distributed Sessions and Persistence. In addition, you can configure the frequency and scope of session persistence. The HADB is also used as the passivation and activation store. Use this option in a production environment that requires session persistence.
The HADB must be configured and enabled before you can use distributed sessions. For configuration details, see the description of the configure-ha-cluster command in the Sun Java System Application Server 9.1 Reference Manual.
To enable the HADB, select the Availability Service component under the relevant configuration in the Admin Console. Check the Instance Level Availability box. To enable availability for the web container, select the Web Service Availability tab, then check the Availability Service box. All instances in an Application Server cluster should have the same availability settings to ensure consistent behavior. For details, see the Sun Java System Application Server 9.1 High Availability Administration Guide.
To change settings such as persistence frequency and persistence scope for the entire web container, see the description of the configure-ha-persistence command in the Sun Java System Application Server 9.1 Reference Manual.
To specify the ha persistence type for a specific web application, edit the sun-web.xml file as in the following example. Note that persistence-type must be set to ha. This overrides the web container availability settings for the web application.
<sun-web-app> ... <session-config> <session-manager persistence-type=ha> <manager-properties> <property name=persistenceFrequency value=web-method /> </manager-properties> <store-properties> <property name=persistenceScope value=session /> </store-properties> </session-manager> ... </session-config> ... </sun-web-app>
The ha persistence type supports all the manager properties listed under manager-properties in Sun Java System Application Server 9.1 Application Deployment Guide except sessionFilename, and supports the persistenceScope store property listed under store-properties in Sun Java System Application Server 9.1 Application Deployment Guide.
For more information about the sun-web.xml file, see The sun-web.xml File in Sun Java System Application Server 9.1 Application Deployment Guide.