Thread pool settings
To configure a thread pool that an appserver uses, from the admin console...
Servers | Server Types | WebSphere application servers | server_name | Thread pool
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.
To configure the thread pool for the ORB Service, click...
Servers | Server Types | WebSphere application servers | server_name | Container services | ORB service | Thread Pool Settings
Select either...
- Use the ORB.thread.pool settings associated with the Thread Pool Manager (recommended), and then click ORB thread pool settings, or
- Use the thread pool settings directly associated with the ORB service, and then click Thread pool settings.
Because these 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 does not appear if we click thread pool settings.
Data type String
- Description
A text description of the thread pool.
This field does not appear if we click thread pool settings.
Data type String
- Minimum size
Minimum number of threads to allow in the pool. When an appserver starts, no threads are initially assigned to the thread pool. Threads are added to the thread pool as the workload assigned to the appserver 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 below the number specified in the Minimum size field, even if some of the threads are idle.
This field does not appear if we click thread pool settings.
Data type Integer Default 10
- Maximum size
Maximum number of threads to maintain in the default thread pool.
If the Tivoli Performance Viewer shows the Percent Maxed 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.
Data type Integer Default 50 Recommended 50 (25 on Linux systems)
- 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 admin console does not allow us to set the inactivity timeout to a negative number. To do this modify the value directly in the server.xml file.
Data type Integer Units Milliseconds Default 3500
- Allow thread allocation beyond maximum thread size
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 JVM and the OS. 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 processing of the work items for which they were created is completed. When additional threads are created, a message is logged in the SYSOUT file to let you know that you went beyond the maximum size set for the thread pool.
Data type Boolean Default Not enabled (false)
Related tasks
Tuning the application serving environment
Related
Thread pool collection
Related information
TCP transport channel settings