10.11.5 Session database tuning

While the session manager implementation in WebSphere provides for a number of parameters that can be tuned to improve performance of applications that utilize HTTP sessions, maximizing performance requires tuning the underlying session persistence table. WebSphere provides a first step by creating an index for the sessions table when creating the table. The index is comprised of the session ID, the property ID for multi-row sessions, and the Web application name.

While most database managers provide a great deal of capability in tuning at the table or tablespace level, creating a separate database or instance provides the most flexibility in tuning. Proper tuning of the instance and database can improve performance by 5% or more over that which can be achieved by simply tuning the table or tablespace.

While the specifics vary, depending on you database and operating system, in general, tune and configure the database as appropriate for a database that experiences a great deal of I/O. The database administrator (DBA) should monitor and tune the database buffer pools, database log size, and write frequency. Additionally, maximizing performance requires striping the database or instance across multiple disk drives and disk controllers, and utilizing any hardware or OS buffering available to reduce disk contention.