If your installation uses typical
DB2 defaults for U-lock management and lock size, certain WebSphere Application Server
applications that use container-managed Enterprise beans (CMP beans)
might encounter deadlocks. The likelihood of encountering deadlocks
is entirely dependent on the design and execution pattern of the applications.
The potential for deadlocks increases with the number and frequency
of applications driving concurrent transactions that update the same
areas of the DB2 database. If, given the workload for your applications,
the potential for deadlocks is high, consider using the following
DB2 settings:
RRULOCK(YES)
LOCKSIZE(ROW)
For additional details, see the information about settings for the
internal resource lock manager (IRLM) in your DB2 Installation Guide.
Your applications might qualify for the optimistic approach
to concurrency control management. To determine whether your applications
can use optimistic concurrency control, see the topic about concurrency
control in the z/OS view of the WebSphere Application Server Information
Center.