Control‑M analyzes job execution results by reading the job sysout. Therefore, the SYSDATA portion of the job must be sent to a held output class to prevent it from being printed accidentally before the Control‑M monitor manages to read it.

HLDCLAS is the automatically held output class to which Control‑M sends the job SYSDATA output.

Note: SYSDATA is an IOA term used to designate the data in the following three job sysout data sets:

• job log (console messages)
• expanded JCL
• system output messages

This class is also used for started tasks under JES3. The started task MSGCLASS must be defined under this class. For more information, see Setting MSGLEVEL and started tasks MSGCLASS.

When Control‑M submits a job, Control‑M either adds a MSGCLASS parameter to the job statement or overrides the existing MSGCLASS parameter. When a started task is started, its MSGCLASS is taken

• under JES2, from the STCCLASS
• under JES3, from the appropriate CIPARM statement

For details, see Step 8 – JES considerations.

The job sysout is directed to the class designated in the HLDCLAS installation parameter. A regular automatically-held output class must be specified during installation.

Special precautions should be taken so that the job sysout will not be accidentally purged, or released for printing. At some sites, all jobs in the automatically held output class are purged by an operator command once a day (or more). You can use the following procedure to prevent deletion before Control‑M reads the job sysout:

• Dedicate a special automatically held output class to Control‑M.
• Protect the sysouts in this class from any change, such as by SDSF exits.

This procedure ensures that Control‑M can read the sysout.

If other users are to access the sysout, the following sample parameters should be defined in any job production parameter definition:

ON PGMSTEP ANYSTEP CODES *****

DO SYSOUT OPT C PRM A FRM X

When Control‑M finishes reading the job sysout, it transfers the sysout to the designated output class, where any user can access it.

Note: The sysout can be read by the Control‑M monitor only when the DEST parameter is set to LOCAL.

Special care should be taken when a system programmer formats the JES queue. This procedure usually involves unloading the output queues to a tape, formatting the spool, and then reloading the queues. The monitor should be shut down before the queue is unloaded to a tape, and brought up again only after the queues have been loaded from the tape back to the spool. If this procedure is not followed, Control‑M may assume that the job is lost, that is, purged by an operator, and act accordingly. When you change the HLDCLAS parameter after Control‑M installation, you should also change the class in the INTRDR DD statement of the Control‑M monitor, and in the JCL procedures CTMAESIM and CTMTAPUL.

Note: When one job submits another job, for example, using TSO batch, and the submitted job does not contain a MSGCLASS, the MSGCLASS of the submitting job is used. Since Control‑M changes the MSGCLASS of the job, each job that is submitted by such a job (with no specified MSGCLASS) will use the Control‑M HLDCLAS.