Tuning the Scheduler

The Scheduler component controls task scheduling in Identity Manager.

This section suggests methods for improving Scheduler performance, including:

• General Suggestions for Tuning the Scheduler

• Tuning the Scheduler Server Settings

General Suggestions for Tuning the Scheduler

The following TaskDefinition options determine how the Scheduler handles tasks after they are completed:

• resultLimit — Controls how many seconds a task is allowed to run after the task has completed. The default setting varies for different tasks. A setting of zero immediately removes tasks after completion.

• resultOption — Controls what action is taken when repeated instances of a task are started. The default setting is delete, which removes extra task instances.

These default settings are designed to optimize memory by shortening the lifetime of finished Scheduler tasks. Unless there is a compelling reason to change these settings, use the defaults.

If you want to immediately delete tasks that completed successfully, but you also want to keep tasks containing errors long enough to debug, you can do the following:

• Conditionally delete finished tasks by setting the resultLimit value to a time period that is sufficient for debugging issues.

• Set the resultLimit to zero (or a small value) if no errors (such as WF_ACTION_ERROR is <null/>) are reported at runtime after a WorkflowServices call.

Tuning the Scheduler Server Settings

You can sometimes improve Scheduler performance by adjusting the following settings on the Edit Server Settings page:

• Maximum Concurrent Tasks. Specifies the maximum number of tasks that the Scheduler can run at one time.

  When more tasks are ready to run than the Maximum Concurrent Tasks setting allows, the extra tasks must wait until there is room available or until they are run on another server.

  If too many tasks are being swapped out of memory and sharing CPU time, the overhead slows down performance. Alternatively, setting the maximum too low results in idle time. The Scheduler checks for available tasks every minute, so a waiting task waits at least a minute before being run.

  The default Maximum Concurrent Tasks setting (100) is usually adequate. You can decide whether to adjust this setting up or down based on which tasks are being run in the deployment and by profiling the runtime behavior after the deployment is otherwise complete.

  In some cases, you might want to suspend or disable the Scheduler. For example, if you want a server dedicated to handling the End User interface, disabling the Scheduler will prevent tasks from running on that server. The server would only serve the End User interface pages and store launched tasks for other servers to execute.

• Task Restrictions. Specifies the set of tasks that can execute on the server.

  The Task Restrictions setting can provide a finer granularity of control over what tasks are allowed to run on a server. You can restrict tasks individually or through the server settings.

Recommending generic, optimal settings is not possible because deployments are so different. Scheduler settings must be adjusted differently for each deployment environment.

To Change the Scheduler Server Settings

1. Log in to the Administrator interface.

2. Click the Configure -> Servers -> Scheduler tabs.

3. When the Edit Server Settings page is displayed, adjust the settings as necessary.

   See Editing Default Server Settings for more information.