The Periodic Alert Scheduler
The Periodic Alert Scheduler (ALEPPE) is a concurrent program that automatically checks your scheduled periodic alerts.
How the Periodic Alert Scheduler Works
The Periodic Alert Scheduler runs at each day at 12 AM. When it runs, the Periodic Alert Scheduler looks for all periodic alerts scheduled to be checked that day, and then submits one concurrent request for each scheduled check.
For example, suppose you have two periodic alerts scheduled to be checked today. You scheduled the first alert for 6 AM, and the second for every two hours between 10 AM and 6 PM. The Periodic Alert Scheduler submits three requests. The first request is for the first alert at 6 AM. The second request is for the second alert at 10 AM, with a resubmission interval of two hours thereafter, and an end time of 6 PM. The last request is for the Periodic Alert Scheduler to run again at 12 AM. Every time Oracle Alert checks an alert successfully, it inserts that day's date in the Last Checked field of the Alerts form.
The Periodic Alert Scheduler also checks for any alerts that were scheduled to run the previous day but failed. It does this by looking for alerts that do not have the date and time of the latest scheduled check in the Last Checked field. The Periodic Scheduler resubmits each failed alert to the concurrent manager every day until the alert runs successfully (that is, the error causing it to fail is corrected) or is disabled.
How Oracle Alert Checks an Alert
Oracle Alert performs each action in an action set in sequence. During an alert check, Oracle Alert checks each action set for any defined input values, then substitutes the input values into the alert Select statement and executes it. Oracle Alert then performs each member of the action set in sequence, substituting the defined output variables with the exception data returned by the Select statement.
- If the action set contains a message action, Oracle Alert constructs and sends the message(s).
- If the action set contains a SQL statement script action, Oracle Alert executes the SQL statement script.
- If the action set contains an Operating System script action, Oracle Alert executes the commands in the script provided that the user who started the concurrent manager has adequate privileges to execute all operating system commands defined in the action.
If one of the action set members is an escalation group, Oracle Alert determines which action to perform based on that action's defined escalation level. If one of the action set members is a threshold group, Oracle Alert performs either the detail or the summary action, depending upon the summary threshold defined and the number of exceptions returned by the Select statement.
- If the action set contains a concurrent program request action, Oracle Alert submits the request to the concurrent manager.
1. Once you have successfully installed Oracle Alert, you need to verify that the Periodic Alert Scheduler is active. Choose View Requests from the Help menu to display the Requests window.
You should see a concurrent request with a program name called Periodic Alert Scheduler. Its status should be Pending. See: Using the Requests Window.
You can also navigate to the Concurrent Request form and perform a general query to see if the Periodic Alert Scheduler program is in the concurrent queue. See: Using the Concurrent Request Windows.
2. If the Periodic Alert Scheduler's status is not Pending, navigate to the Schedule Alert Programs form.
3. Select Periodic Alert Scheduler.
4. Choose Activate to start the Periodic Alert Scheduler immediately or enter a value in the Active Date field and then choose Activate to schedule it to start later.
When you start the Periodic Alert Scheduler, Oracle Alert submits it as a concurrent request to the concurrent manager to run every 24 hours at 12 AM. Every time the Periodic Alert Scheduler runs, it submits a request to the concurrent manager to be run again the next day at 12 AM.
5. If the Periodic Alert Scheduler gets deleted from the concurrent queue for any reason, simply restart it from the Schedule Alert Programs form.
6. If you need to deactivate the Periodic Alert Scheduler, choose Deactivate.
Creating a Periodic Alert
Defining a Summary Threshold