Queueing Output

Normally, output data produced by a job is placed in one of three output service queues when the job terminates. Spin-off data sets are placed in an output queue while the job is still in execution. The three output queues are:

MVS/BDT work queue (Q=BDT): This queue contains SNA/NJE networking job or networking system output streams. MVS/BDT sends these job or system output streams to the proper node within a SNA/NJE network. You can use JES3 operator commands to hold, release, or cancel networking requests from the queue.
Output service writer queue (Q=WTR): This queue contains data sets waiting for output processing by JES3 managed devices. Output service automatically selects data sets for processing based on their selection characteristics such as output class, output priority, and output device-related requirements. You can use JES3 commands to place these data sets in operator-hold status. You can also use JES3 commands to modify a data set's selection characteristics or move the data set to the HOLD queue.
Note: Process SYSOUT and System Application Printer Interface can also process work on the output service writer (WTR) queue.
Output service hold queue (Q=HOLD): This queue contains data sets that are awaiting output processing by other than JES3-managed devices. These data sets must be processed by the function for which they are held (System Application Printer Interface (SAPI) application, external writer or TSO). The function that processes the data set can then change data set characteristics, release it for JES3 processing, or cause JES3 to purge it. If necessary, the operator can force a JES3 writer to process the data set or issue a modify (*F) command to move the data set to the WTR for JES3 device processing.

You can use the JES3 *INQUIRY U and *MODIFY U commands to inquire about, modify, or delete data sets on the writer, hold, or BDT queue. For information about using these JES3 commands, see z/OS JES3 Commands.

The RESQUEUE entry for the job to be processed by the queueing function is placed on a queue of output service work. When the queueing function receives control, it dequeues the next job on the work queue.

The queueing function of output service accesses the job data set (JDS) for the job or for the spin data sets of a job. The queueing function builds output scheduling elements (OSEs) from the JDS. One OSE is built for each group of data sets that have unique writer requirements.

The information in an OSE for output data sets on the writer queue comes from:

JCL parameters on the SYSOUT DD and OUTPUT JCL statements for the job (The installation can change these parameters during input service by coding installation exit routine IATUX34 for the SYSOUT DD statement and installation exit routine IATUX44 for the OUTPUT statement.)
The //*FORMAT JES3 control statements for the job (The installation can change these statements during input service by coding installation exit routine IATUX33.)
The SYSOUT class table (defined by SYSOUT initialization statements)

Note: The installation can change the characteristics in the OSE by coding the installation exit routine, IATUX19.

Information from //*FORMAT control statements is not included in OSEs for data sets on the hold queue.

When moving data sets from the hold queue to the writer queue, default and direct //*FORMAT statements are applied to the SYSOUT characteristics of the SYSOUT on the writer (WTR) queue.

The OUTSERV initialization statement specifies default values for information not provided on other JES3 initialization statements or on JCL statements. If the OUTSERV initialization statement parameters are not overridden, the default values specified are applied to all jobs entered in the system. You override the OUTSERV initialization statement parameters with appropriate parmaters on JCL or through particular DEVICE initialization statement parameters for those devices producing output. See z/OS JES3 Initialization and Tuning Reference for detailed descriptions of the OUTSERV and DEVICE initialization statements and their relationship to the JCL of jobs.