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If you click Generational Concurrent Garbage Collector, the Java heap is divided into a
new area (nursery), where new objects are allocated, and an old area (tenured space), where
longer-lived objects are located. The total heap size is the sum of the new area and the
tenured space. You can set the new area size independently from the total heap size.
Typically, set the new area size in the range of 1/4 and 1/2 of the total heap size. The relevant
parameters are as follows:
► Initial new area size: Xmns
► Maximum new area size: Xmnx
► Fixed new area size: Xmn
4.3.3 Message-driven bean ActivationSpec
To access the MDB ActivationSpec tuning parameters, more than one shortcut is available in
the administrative console:
►
►
Click Resources Resource Adapters J2C activation specifications. Select the
name of the application specification you want to access.
Click Resources Resource Adapters Resource adaptersSelect the name of the
resource adapter you want to access. Then click Additional properties J2C
activation specifications. Select the name of the activation specification you want.
The following custom properties in the ActivationSpec message-driven bean (MDB) have
considerable performance implications. These properties are described further in “Tuning
message-driven bean ActivationSpec properties” on page 64.
► maxConcurrency
► maxBatchSize
4.3.4 Thread pool sizes
Business Process Manager servers use thread pools to manage concurrent tasks. You can
set the Maximum Size property of a thread pool in the administrative console by clicking
Servers Application servers and selecting the server name whose thread pool you want
to manage. Click Additional Properties Thread Pools and then the thread pool name.
You typically must tune the following thread pools:
► Default
► ORB.thread.pool
► WebContainer
In addition, thread pools that are used by Work Managers for BPEL processes are configured
separately in the console by clicking Resources Asynchronous beans Work
managers. Select the Work Manager name and then click Thread pool properties
You typically must tune the following Work Managers:
► DefaultWorkManager
► BPENavigationWorkManager
54 IBM Business Process Manager V8.0 Performance Tuning and Best Practices