Smart Plug-in for WebLogic Server Reference Guide

Chapter 1
Metric B225_EJBFreePoolWtRt
1-29
Instruction Text The number of times per minute no EJBs were available from the free pool has
exceeded the threshold value.
Probable cause: The max-beans-in-free-pool element may have been set too
low, or all instances of an EJB class may be active.
Potential impact: New clients requesting an EJB class will be blocked until an
active EJB completes a method call.
Suggested action: When EJBs are created, the session bean instance is created
and given an identity. When the client removes a bean, the bean instance is
placed in the free pool. When you create a subsequent bean, you can avoid
object allocation by reusing the previous instance that is in the free pool. The
max-beans-in-free-pool element can improve performance if EJBs are
frequently created and removed.
The container creates new instances of message beans as needed for concurrent
message processing. The max-beans-in-pool element puts an absolute limit on
how many of these instances will be created. The container may override this
setting according to the runtime resources that are available.
For the best performance for stateless session and message beans, use the
default setting max-beans-in-free-pool element. (The default is no limit.) This
way, you can run as many beans in parallel, using as many threads as possible.
The only reason to change the setting would be to limit the number of beans
running in parallel or to limit access to an underlying resource. For example, if
you use stateless session EJBs to implement a legacy connection pool, you do
not want to allocate more bean instance than the number of connections that can
be supported by your legacy system.
For information on tuning EJB parameters, see the 'Performance and Tuning'
documentation for your WebLogic Server version available through
http://e-docs.bea.com/.
Action
Area EJB
Monitor Template Name WLSSPI_0225