
Tuning the Enterprise Server for
Session Persistence Scope
You can specify the scope of the persistence in addition to persistence frequency on the same page in the Admin Console where you specify persistence frequency, Configurations >
For detailed description of different persistence scopes, see Chapter 7, “Configuring High Availability Session Persistence and Failover,” in Sun GlassFish Enterprise Server 2.1 High Availability Administration Guide.
Persistence scope can be one of:
■session
■
■
session
With the session persistence scope, the server writes the entire session data to
modified-session
With the
modified-attribute
With the
Session Size
It is critical to be aware of the impact of HTTP session size on performance. Performance has an inverse relationship with the size of the session data that needs to be persisted. Session data is stored in HADB in a serialized manner. There is an overhead in serializing the data and inserting it as a BLOB and also deserializing it for retrieval.
Tests have shown that for a session size up to 24KB, performance remains unchanged. When the session size exceeds 100KB, and the same
118 | Sun GlassFish Enterprise Server 2.1 Performance Tuning Guide • January 2009 |