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Monday, May 5, 2008

Defining Background Jobs

 

Starting background jobs is a two−step process: you first define the job and then you have to release it.

 

When users define a job and save it, they are actually scheduling the report, that is, specifying the job components, the steps, the start time, and the print parameters. So, to schedule a job is the same thing as to define it. More precisely a scheduled job is a job definition which has been saved.

When users schedule programs for background processing, they are instructing the system to execute an ABAP report or an external program in the background.

 

Scheduled background jobs, however, are not actually executed until they are released. When jobs are released, they are sent for execution to the background processing system at the specified start time.

Jobs are released automatically if the user is authorized to release jobs, and they automatically start the execution in the background system if the user has chosen the start immediately option.

Both the scheduling and the releasing of jobs require authorizations. Standard SAP users have authorization which allow them to schedule jobs; however, releasing jobs is a task normally assigned to the system administration and requires another authorization. Protecting the releasing of jobs with authorization enables system administrators to better monitor and maintain the background system and allows the available resources to be better distributed. The drawback is that scheduling jobs is such a common task that it can surpass the administrator's ability to maintain the whole system. Therefore, reserve some time for studying which users should be allowed to release their own jobs.

 

When users do not have release authorization, the start time or frequency they specify does not have any affect at all, except for informing the administrator in charge of releasing them of their preference for executing the job. Administrators or users with authorization for releasing jobs can change the start time

specifications and the interval.

 

When scheduling jobs, users can specify several steps, each having a different report or program. Each step has its own attributes, such as authorized users or print parameters. The same job can contain steps with ABAP reports and steps with external programs or commands.

 

When defining jobs, users also have the option of scheduling a program as a separate job or modifying an existing job which has not yet been processed and adding it to the list of job steps.

Users, and especially administrators, should avoid having too many released jobs during normal, operative working hours, since the system processes the background jobs during online operation where there are available background work processes. Remember that a background job will perform the same tasks as if the functions were performed online. So, if a background job does lock a table or updates the database, it will have an immediate result and can affect the work of online users.

 

 

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