Http Session Tuning - Write Frequency

In the Session Management facility, you can configure the frequency for writing session data to the database or to a WebSphere instance, depending on whether you use database distributed sessions or memory-to-memory replication. This flexibility enables you to weigh session performance gains against varying degrees of failover support.





The following options are available in the Session Management facility for tuning write frequency:

• End of service servlet- Write session data at the end of the servlet service method call.


• Manual update- Write session data only when the servlet calls the IBMSession.sync method.


• Time based (the default) - Write session data at periodic intervals, in seconds (called the write interval).

When a session is first created, session information is always written at the end of the service call.Using the time based write or manual update options can result in loss of data in failover scenarios since the backup copy of the session in the persistent store (for example, a database or another JVM) may not be in sync with the session in the session cache.