The Loader class implements the Schedulable interface, which enables it to be run automatically on a specified schedule. By default, each loader component is configured to start up once a day and run for a period of several hours. When a loader first starts up, it checks the corresponding queue to see if there are entries for any log files. If so, the loader claims an entry and begins to process the file. When it finishes processing the file, the loader checks the queue again, and if there are any more entries, claims another entry and processes that file. This process continues until there are no more entries in the queue.
If there are no entries in the queue, the loader sleeps for a specified period of time, and then checks again. If at this point the queue is still empty, the loader sleeps again. This process continues until a specified time, at which point the loader stops checking and waits until the next scheduled start time.
The schedule for starting up the loader is specified by the component’s runSchedule property. This property is a CalendarSchedule object that is set by default to run the loader once each day. The schedule for shutting down the loader is specified by the component’s stopSchedule property. This property is also a CalendarSchedule object, and is set by default to shut down the loader once each day, several hours after the component starts up. You can change these settings to run the loader on a different schedule.
The period of time (in milliseconds) that the loader sleeps if there are no entries in the queue is set by the component’s noLoadSleepMillis property. The default value of this property is 600000 (equivalent to 10 minutes).
For more information about scheduler components and properties, and the syntax used to set those properties, see the Core Dynamo Services chapter of the Platform Programming Guide.
