(iSeries)
(Dist) Thread pool settings
Configure a thread pool an application server uses. A thread pool enables components of the server to reuse threads, which eliminates the need to create new threads at run time. Creating new threads expends time and resources.
(ZOS) This page does not display for z/OS because thread pools are not used in a z/OS environment.
From the admin console, click...
Servers > Server Types > WebSphere application servers > server > Thread pools, and select the thread pool needed to configure.
To configure the thread pool for the ORB Service, click...
Servers > Server Types > WebSphere application servers > server > Container services > ORB service. Under Thread Pool Settings, select one of the following actions:
- Select Use the ORB.thread.pool settings associated with the Thread Pool Manager> ORB thread pool settings, or
- Select Use the thread pool settings directly associated with the ORB service> Thread pool settings.
Because these administrative console panels display information dynamically, we might not see all of the fields listed on any particular panel.
Name
The name of the thread pool to create. The name must be unique within the server.
This field is not displayed if you click thread pool settings.
Information Value Data type String
Description
A text description of the thread pool.
This field is not displayed if you click thread pool settings.
Information Value Data type String
Minimum size
Minimum number of threads to allow in the pool. When an application server starts, no threads are initially assigned to the thread pool. Threads are added to the thread pool as the workload assigned to the application server requires them, until the number of threads in the pool equals the number specified in the Minimum size field. After this point in time, additional threads are added and removed as the workload changes. However, the number of threads in the pool never decreases beneath the number specified in the Minimum size field, even if some of the threads are idle.
This field is not displayed if you click thread pool settings.
Information Value Data type Integer Default 50
Maximum size
Maximum number of threads to maintain in the default thread pool.
If our Tivoli Performance Viewer shows the Percent axed metric to remain consistently in the double digits, consider increasing the Maximum size. The Percent Maxed metric indicates the amount of time that the configured threads are used.
Information Value Data type Integer Default 50
Thread inactivity timeout
Number of milliseconds of inactivity that should elapse before a thread is reclaimed. A value of 0 indicates not to wait and a negative value (less than 0) means to wait forever.
The administrative console does not allow you to set the inactivity timeout to a negative number. To do this we must modify the value directly in the server.xml file.
Information Value Data type Integer Units Milliseconds Default 60000 For transitioning users: The default value was changed in version 8.0 from 35000 milliseconds as documented in version 6.0 to the correct default of 60000 milliseconds.trns
Allow thread allocation beyond maximum thread size
Specifies whether the number of threads can increase beyond the maximum size configured for the thread pool.
The maximum number of threads that can be created is constrained only within the limits of the Java virtual machine and the operating system. When a thread pool that is allowed to grow expands beyond the maximum size, the additional threads are not reused and are discarded from the pool after required work items are completed.
Information Value Data type Boolean Default Cleared
Tune the application serving environment Thread pool collection TCP transport channel settings