Configuring 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. You can write session data using the end of service servlet, manual update or time based update options.

About this task

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.

If you are using the time based write option, when a server shuts down, the server typically attempts to write the latest session data, that is in the session cache, to the persistent store, as part of the shutdown process.

Using the time based write or manual update options can result in the loss of data in failover scenarios because the backup copy of the session in the persistent store, such as a database, or another JVM, might not be in sync with the session in the session cache.

Procedure

  1. Go to the appropriate level of Session Management.
  2. Click Distributed environment settings
  3. Click Custom tuning parameters.
  4. Click Custom settings.
  5. Select the method of write frequency that you want to use.
  6. Click OK.