EJB cache settings

To configure and manage the cache for a specific EJB container.

Console | Servers | Application Servers | serverName | EJB Container | EJB Cache Settings

To determine the cache absolute limit, multiply the number of enterprise beans active in any given transaction by the total number of concurrent transactions expected. Then, add the number of active session bean instances. Use the Tivoli Performance Viewer to view bean performance information.


Configuration tab

Cleanup interval Interval at which the container attempts to remove unused items from the cache in order to reduce the total number of items to the value of the cache size.

The cache manager tries to maintain some unallocated entries that can be allocated quickly as needed. A background thread attempts to free some entries while maintaining some unallocated entries. If the thread runs while the appserver is idle, when the application server needs to allocate new cache entries, it does not pay the performance cost of removing entries from the cache. In general, increase this parameter as the cache size increases.

Data type Integer
Units Milliseconds
Range 0 to 2 147 483 674
Default 3000

Cache size Number of buckets in the active instance list within the EJB container.

A bucket can contain more than one active enterprise bean instance, but performance is maximized if each bucket in the table has a minimum number of instances assigned to it. When the number of active instances within the container exceeds the number of buckets, that is, the cache size, the container periodically attempts to reduce the number of active instances in the table by passivating some of the active instances. For the best balance of performance and memory, set this value to the maximum number of active instances expected during a typical workload.

Data type Integer
Units Buckets in the hash table
Range Greater than 0. The container selects the next largest prime number equal to or greater than the specified value.
Default 2053


See Also

Managing EJB containers
Tuning performance parameter index
EJB container settings