In addition to being able to schedule events, you can also accomplish the following management tasks by using the Cold Fusion Administrator:
• Editing an existing scheduled event
• Deleting an existing scheduled event
• Controlling the refresh interval
Editing an Existing Scheduled Event
The Cold Fusion Administrator provides the means to view or change the settings of any previously scheduled event. This is accomplished via the Scheduled Tasks page of the Administrator.
As scheduled events appe:ar in a list on the Scheduled Tasks page. The name of each event is a link. Clicking the link opens the Edit Scheduler Task page, which has all the same fields as the Add Scheduler Task page. As the Edit Scheduler Task page has all the fields preset with the settings for the selected task.
After changing settings as needed, the changes can be saved by clicking the Update button at the bottom of the page.
Deleting an Existing Scheduled Event
To delete a scheduled event, click its link on the Scheduled Tasks page. This brings up the Edit Scheduler Task page (shown earlier in Figure 28.9). Click the Delete button at the bottom of the page to delete the task.There is no confirmation when deleting a scheduled event, so be sure that you have selected the correct task before deleting it.
Running an Existing Scheduled Event
You can run an existing scheduled event manually at any time by clicking the Run link in the event’s entry on the Scheduled Tasks page. Cold Fusion will run the task and will generate its output to a log file or by mail as specified in the event) settings. No confirmation
of the success of the task will be displayed in the ColdFusion Administrator.
Controlling the Refresh Interval
When a new task is scheduled, it is added to the list of scheduled tasks-but the scheduler that executes scheduled tasks is not aware of the new task. The scheduler checks the list for new tasks on a regularly scheduled basis, and only from that time on is it aware of a task, and can execute it as scheduled.
What happens if you schedule a task to execute before the scheduler next polls the list for new tasks? The task will fail to execute. By default, the scheduler refreshes its list of active tasks at an interval of 15 minutes. If this interval is too large or too small for the needs of a particular server, it can be changed on the Scheduler Setting page of the Cold- Fusion Administrator.
Here there is only one value to set: the interval in minutes between each successive check for new tasks by the scheduler. Changing.this value to a low setting (such as every one or two minutes) when the list of tasks is large could impose an unnecessary load on a busy ColdFusion server. For most purposes, the default IS-minute interval should prove sufficient.
Where Do We Go from Here?
In thenext chapter, you will move on to another advanced topic that ColdFusion helps make simple: implementing a search engine. Most large Web sites offer a search facility in which users can search by keywords (and sometimes even with plain English questions) to find just the right page within a site. ColdFusion integrates the Verity search engine into the Cold Fusion server, making it possible to create fast, easy-to-manage search engines for even the ‘largest Web sites. In the next chapter, you will learn how to set up, implement, and maintain a search engine by using ColdFusion and the Verity search engine.