Purpose

To allow the creation and maintenance of batch queues

Subsystem

Job Control and Scheduling

Structure

Two Blocks

Batch Queue

Batch Queue Priority Restriction

Image

Batch Queue

Explanation

This form allows the creation and management of batch queues. All batch queues are associated with a run window, and become available during that run window's intervals. Jobs are assigned automatically to active batch queues by the JBS subsystem - but by changing details using this form, the flow of jobs through the system can be tuned in the following ways:

• a batch queue can be suspended
• its run window can be changed
• the periods when it runs within a run window can be further limited
• it can be set up so that only jobs with a certain priority or priorities can use it.

To create a new batch queue record using the Maintain Batch Queue Details form:

In Insert mode:

1. Enter a number (1 - 99) to identify the new batch queue, in Queue ID.
2. Enter a description.
3. Either
   key a valid run window value in the Run Window field
   or
   using the icon alongside the field ,
   access the pop-up window, Inquire On Run Windows (JBSF4411), and select the required run window using that form.
4. Optionally, enter a start and end time in the Start Time and End Time fields to delimit the run window intervals further.
5. Save.

• Batch queues are automatically set to INACTIVE when outside their run window.
• With start and end times set, a job can only start within the specified period. For example, in a business hours run window with intervals set for 8:00 to 17:30, Monday to Friday, and batch queue start and end times set to 15:00 and 10:00 respectively, a job can start in this queue between 8:00 and 10:00 and between 15:00 and 17:30.
• Jobs in a request are allocated only to batch queues with the same run window as the request.

To modify a batch queue record using the Maintain Batch Queue Details form:

1. Find the record to be modified by query.
2. Modify the record as required.
3. Save.

• Batch queues can be SUSPENDED at any time.

To delete a batch queue record using the Maintain Batch Queue Details form:

• Batch queues cannot be deleted. To prevent jobs running against a batch queue, set the System Queue Status to SUSPENDED.

Batch Queue Priority Restriction

Explanation

One or more priorities can be recorded here, in order to restrict the batch queue to jobs with the same priority. When a job is assigned to a batch queue, the JBS subsystem routine attempts first to assign it to one with appropriate priority restrictions. This means, for instance, that a priority one job will be assigned to a batch queue with a priority one restriction in preference to any other queue, if the priority one queue is free to run it.

Example

In the instance given above, restricting a batch queue to priority one increases the likelihood that there will be a queue available to run priority one jobs as soon as their scheduled time arrives.

Conversely, a queue can be set aside for low priority jobs. This may be a temporary measure only, to allow the running of a low priority job which has been held up for a long time because higher priority jobs are constantly being submitted.

To record a priority restriction against a batch queue record, using the Maintain Batch Queue Details form:

1. Insert or select a blank record.
2. Select a priority from the list of values, or key a number from 1 to 9, in the Job Priority field.
3. Repeat from 1 for further priority values.
4. Save.

• Priority 1 is the highest priority.

To delete a priority restriction against a batch queue record, using the Maintain Batch Queue Details form:

1. Find the record to be deleted.
2. Locate the cursor in the record to be deleted.
3. Delete record.
4. Save.

Changes within this form will have the following notable effects:

• Changes in this form may affect the time it takes for scheduled jobs to start running, or may prevent some jobs from running because there is no active batch queue available with the same run window and priority.