Each thread group has a run interval, which determines how often the Thread Manager calls the run method. The run interval can be:
Run interval |
Meaning |
|---|---|
A positive integer n |
The Thread Manager calls run repeatedly, waiting approximately n seconds after each time the run method returns. The actual time can vary depending on scheduling of calls to other methods and the server’s processing load. |
0 |
The Thread Manager calls run repeatedly, with no waiting between invocations. |
-1 (the default) |
The Thread Manager calls run only once. |
To allow threads to be stopped or suspended, you must configure a positive or 0-length run interval and code each component’s run method to perform a repetitive task, then return. The run interval has no effect if your run method never returns.
If the run interval is positive or 0, you can change the run interval after threads have been started in the group, the change takes for each thread when it returns from the run method. You cannot change the interval to -1, and changing the interval does not affect threads started with the interval set to -1. In these cases, calling setRunInterval has no effect.
You can use a run interval to schedule periodic tasks, such as refreshing a cached copy of a database query result. You can also tune how much CPU time your component consumes if it performs CPU-intensive tasks such as lengthy calculations; such tuning also requires that you adjust the amount of work done in each invocation of the run method.
You can also use the Message Service to schedule periodic background processing. For example, you can configure a run interval of -1 (so Thread Manager calls run once only) and schedule another component to start threads at the desired interval. See “Subscribing to scheduled messages” for more information.
