External writer sysout
- A SYSOUT class is used which has HOLD=EXTWTR specified.
- An external writer name is specified on the DD JCL statement.
- An external writer name is specified using the WRITER= parameter on an OUTPUT JCL statement.
- Transmitted sysout is received with an external writer name specified in the network header.
Sysout data sets waiting to be processed by an external writer are always held on the output service hold queue (Q=HOLD). The held sysout may have no output disposition set, or may have an output disposition of HOLD, KEEP, LEAVE, or WRITE.
Sysout data sets held for an external writer are made available for processing when no output disposition is set or the output disposition is WRITE or KEEP. Sysout with output disposition of HOLD or LEAVE are not made available for processing unless explicitly requested such as by applications using the SYSOUT Application Program Interface.
After processing a sysout data set, an external writer application can then request that JES3 release the sysout. For sysout with no output disposition set or with an output disposition of WRITE, a release request results in JES3 releasing the sysout for an output service writer. The sysout is moved to the output service writer queue (Q=WTR) for processing by an output service writer. A release request for sysout with an output disposition of KEEP results in the sysout remaining held for an external writer on Q=HOLD and the disposition of the sysout is updated to LEAVE. Sysout with an output disposition of HOLD or LEAVE that is processed and released by an application, remains held for an external writer on Q=HOLD with no change to the output disposition.
An external writer application can also request that JES3 delete the sysout after processing. Except for sysout with an output disposition of KEEP, a delete request causes the sysout to be purged. For sysout with an output disposition of KEEP, the delete request results in the sysout remaining held for an external writer on Q=HOLD and the disposition of the sysout is updated to LEAVE.
The *MODIFY,U command can also be used to change the output disposition of the sysout or modify the queue on which the sysout resides. For more information see Changing job output *MODIFY,U.
