Server User Manual

It is important to pay attention while determining the HTTP session size. If you are creating
large HTTP session objects, calculate the HADB nodes as discussed in
“Tuning HADB” on
page 107
.
Checkpointing Stateful Session Beans
Checkpointing saves a stateful session bean (SFSB) state to the HADB so that if the server
instance fails, the SFSB is failed over to another instance in the cluster and the bean state
recovered. The size of the data being checkpointed and the frequency at which checkpointing
happens determine the additional overhead in response time for a given client interaction.
You can enable SFSB checkpointing at numerous dierent levels:
■
For the entire server instance or EJB container
■
For the entire application
■
For a specic EJB module
■
Per method in an individual EJB module
For best performance, specify checkpointing only for methods that alter the bean state
signicantly, by adding the <checkpointed-methods> tag in the sun-ejb-jar.xml le.
Conguring the JDBC Connection Pool
The Enterprise Server uses JDBC to store and retrieve HADB data. For best performance,
congure the JDBC connection pool for the fastest possible HADB read/write operations.
Congure the JDBC connection pool in the Admin Console under Resources > JDBC >
Connection Pools > pool-name. The connection pool conguration settings are:
■
Initial and Minimum Pool Size: Minimum and initial number of connections maintained
in the pool (default is 8)
■
Maximum Pool Size: Maximum number of connections that can be created to satisfy client
requests (default is 32)
■
Pool Resize Quantity: Number of connections to be removed when idle timeout timer
expires
■
Idle Timeout: Maximum time (seconds) that a connection can remain idle in the pool.
(default is 300)
■
Max Wait Time: Amount of time (milliseconds) caller waits before connection timeout is
sent
Tuning the Enterprise Server for High-Availability
Chapter 6 • Tuning for High-Availability 119