Controlling print data sets

Application programs have some control over the IMS Spool API files IMS creates for them. This control applies to the data streams generated by the application program as well, because IMS is not sensitive to this data.

You can embed control information within the data stream itself, or you can specify the IMS Spool API file options in an application program DL/I CHNG call. These processing options are specified on a data set basis and are specified on the TSO OUTDES statement.

The IMS Spool API routes print data based on output scheduling. Generally, scheduling is determined by output class (CLASS parameter), printer destination (DEST parameter), FORM, and PRMODE.

IMS is a transparent delivery service. IMS dynamically creates IMS Spool API files based on data set processing options, writes the messages to them, and then deallocates them so that they can be processed by an IMS Spool API data set server (such as PSF).

To ensure proper disposition of print data sets, the z/OS® operator might need to become involved under certain conditions, such as:

• IMS emergency restart
• Dependent region abnormal termination
• Dynamic deallocation failure for a print data set

Under such conditions, the z/OS operator must deal appropriately with the IMS Spool API data sets that represent in-doubt messages. IMS provides informational messages to help the z/OS operator if the application program requests the proper disposition of these data sets.

Review operational procedures for unprintable data sets at your installation. Many installations have jobs that delete print data sets after a given number of days. Make sure that these jobs do not delete IMS print data sets that should be printed.