Job-Related Considerations for Pipes

The following job-related issues must be considered when using the PIPE parameter in a Control-M job scheduling definition:

• When using pipes for jobs submitted by Control-M, the PIPE parameter must be used if parallel submission of all pipe participants is to be ensured.
• Normally (that is, when pipes are not used), prerequisite conditions ensure desired flow of predecessor and successor jobs.

  However, when values are specified in the PIPE parameters of interrelated job scheduling definitions, Control-M uses them to create Collections. The jobs in a Collection are not submitted until all prerequisite conditions required by all jobs in the Collection are satisfied. If a dependency exists between an OUT condition of one job and an IN condition of another job in the same Collection, it prevents submission of all the jobs in the Collection. Control-M resolves this problem by ignoring the IN condition, thus bypassing the dependency between the jobs in the Collection and enabling the submission of the jobs. If the job is removed from the Collection, its ignored IN conditions reappear.

• When two jobs in the same Collection request the same Control resource, and at least one of them requests the resource in "exclusive" mode, a "deadlock" situation arises—the Collection jobs are not submitted. To prevent this, Control-M ignores the Control resource requests of one of the jobs, as follows: If one of the jobs requested the resource in "shared" mode, that resource request is ignored; if both jobs requested the resource in "exclusive" mode, the resource request of the job with the shorter average elapsed time is ignored. If the job is removed from the Collection, its ignored Control resources reappear.

  Note: To allow integration between Control-M and MVBO/Job Optimizer Pipes, the pipe name specified in the Control-M job scheduling definition must be identical to the pipe name specified in the MVBO/Job Optimizer Pipes rule. Currently, this requirement is not forced by Control-M.

• Jobs cannot be run in parallel if TIME FROM and TIME UNTIL specifications for the jobs do not overlap.

  This case must be considered individually at time of implementation.

• When PIPE definitions are added, the Quantitative resources defined for the jobs in the Collection must be checked to see if some of the defined resources are no longer necessary. For example, if a pipe replaces a tape data set, the tape resource may not be required. Such resources must be removed from the job scheduling definition.
• In a non-Sysplex environment, all jobs that are part of a Collection must run in the same system. Therefore, BMC recommends that you avoid using resources prefixed by a dollar sign ($) in jobs that are part of a Collection, to ensure that all the jobs are submitted to the same system.