Most server-side applications have tasks that need to be performed on a periodic or recurring basis. For example, a component in the application may need to clear a cache every 10 minutes, or send out e-mail at 2AM every morning, or rotate a set of log files on the first of every month.
Dynamo includes a Scheduler service, atg.service.scheduler.Scheduler, which keeps track of scheduled tasks and executes the appropriate services at specified times. Administrators can see a list of all scheduled tasks by looking up /atg/dynamo/service/Scheduler in the Component Browser.
Dynamo also includes a SingletonSchedulableService, atg.service.scheduler.SingletonSchedulableService, which enables multiple Dynamo servers to run the same scheduled service, while guaranteeing that only one instance of the service will perform the scheduled task at any given time. This provides a degree of protection from server failures, since the loss of any single Dynamo server will not prevent the scheduled service from running on some other Dynamo server.
