Managing the print queues

Whenever a print job is received by NPF, the capture point application creates a temporary QSAM print data set and adds a record to the queue file for each destination to which that print data is to be sent. For a multiple-destination routing only, an extra record is also written to act as an end-of-set marker.

The queue manager then assumes responsibility for all further processing of the print data set and the queue file records which point to it. Queue manager functions are listed as follows:

Determining the order in which print jobs should be scheduled. For any given printer, print jobs are sent in FIFO (First In, First Out) order based on arrival time.
Sending print data to LPD, including both initial send attempts and retries.
Evaluating the return code from the send attempt and determining which of the following actions is needed:
- After a successful transmission, keeping the queue record for a user-specified retain time or erasing the queue record immediately.
- After an unsuccessful transmission, setting up the queue record for a retry of the send, keeping the queue record for a user-specified retain time, or erasing the queue record immediately.
Erasing a queue record after its user-specified retain time has expired.
Deleting a QSAM print data set after the last queue file record which points to it has been erased.

Each record on the queue file contains a data set status field. Possible values for this field and their meanings are as follows:

Z: No send attempted yet. Normal next action is the initial attempt to send the print data.
U: Last send unsuccessful; one or more retries left. Normal next action is a retry of the failed send operation.
R: Last send unsuccessful; all retries exhausted; queue record being kept for the RETAIN(U) retain time. Normal next action, after the RETAIN(U) interval expires, is to erase the queue record and, if this is a single-destination routing, delete the corresponding print data set.
T: Last send successful; queue record being kept for the RETAIN(S) retain time. Normal next action, after the RETAIN(S) interval expires, is to erase the queue record and, if this is a single-destination routing, delete the corresponding print data set.
H: Print job being held. The queue record is kept, but no processing is done for it while in this state.
X: End-of-set marker for a multiple-destination routing. The purpose of this record is to make sure that the QSAM print data set is not deleted until all queue records which point to it have been erased. Records with this state are displayed by the ISPF interface, but you cannot make any changes to them.
D: Delete. Records with this state have been marked for deletion by a panel operator but not yet erased by the queue manager. These records are never displayed by the ISPF interface.