Asynchronous HTTP Session Replication using a Secondary Server Asynchronous HTTP Session Replication using a Database

Tuning WebLogic Server 7-13

7.7.5.1 Asynchronous HTTP Session Replication using a Secondary Server

Set the PersistentStoreType to async-replicated or async-replicated-if-clustered to specify asynchronous replication of data between a primary server and a secondary server. See session-descriptor section of Developing Web Applications, Servlets, and JSPs for Oracle WebLogic Server. To tune batched replication, adjust the SessionFlushThreshold parameter. Replication behavior depends on cluster type. The following table describes how asynchronous replication occurs for a given cluster topology. The following section outlines asynchronous replication session behavior: ■ During undeployment or redeployment: – The session is unregistered and removed from the update queue. – The session on the secondary server is unregistered. ■ If the application is moved to admin mode, the sessions are flushed and replicated to the secondary server. If secondary server is down, the system attempts to failover to another server. ■ A server shutdown or failure state triggers the replication of any batched sessions to minimize the potential loss of session information.

7.7.5.2 Asynchronous HTTP Session Replication using a Database

Set the PersistentStoreType to async-jdbc to specify asynchronous replication of data to a database. See session-descriptor section of Developing Web Applications, Servlets, and JSPs for Oracle WebLogic Server. To tune batched replication, adjust the SessionFlushThreshold and the SessionFlushInterval parameters. The following section outlines asynchronous replication session behavior: ■ During undeployment or redeployment: – The session is unregistered and removed from the update queue. – The session is removed from the database. ■ If the application is moved to admin mode, the sessions are flushed and replicated to the database. Table 7–3 Asynchronous Replication Behavior by Cluster Topology Topology Behavior LAN Replication to a secondary server within the same cluster occurs asynchronously with the async-replication setting in the webapp. MAN Replication to a secondary server in a remote cluster. This happens asynchronously with the async-replication setting in the webapp. WAN Replication to a secondary server within the cluster happens asynchronously with the async-replication setting in the webapp. Persistence to a database through a remote cluster happens asynchronously regardless of whether async-replication or replication is chosen. 7-14 Performance and Tuning for Oracle WebLogic Server

7.7.6 Invalidation of Entity EJBs