Updating Procedure Libraries

If you want to update one or more procedure libraries, you must ensure the integrity of the procedure libraries by letting JES3 know which data set(s) your job will update. List the names of the data set(s) to be updated on the UPDATE parameter of the //*MAIN JES3 control statement for that job. Before the job enters setup processing, JES3 disables all procedure libraries containing those data sets. JES3 and the C/I FSS address spaces, if any, deallocate the procedure libraries so that C/I service cannot use them. However, another job can update those procedure libraries if the job updates different data sets in the library concatenation.

The procedure libraries remain inaccessible (disabled) to C/I service until the updating job(s) finish executing. Other jobs needing those procedure libraries for C/I service must wait. To avoid making other jobs wait for long periods, keep updating jobs brief, with simple setup requirements. Jobs using other procedure libraries are not affected.

When the updating job(s) finish executing, JES3 reallocates the procedure libraries to JES3 and the C/I FSS address spaces. JES3 enables the procedure libraries when no more data sets in the procedure libraries are being updated.

If a job updating a procedure library is placed in spool hold over a restart, the procedure library remains disabled until the job is released from hold and all the processing described above finishes.

If a job updating a procedure library moves any procedure library data set to another volume, the job must update the catalog entry for that data set on all processors having C/I FSS address spaces. Otherwise, C/I service cannot find the correct catalog entry to enable the procedure libraries after the job finishes executing. When the procedure libraries are enabled, JES3 updates or verifies other information about the updated procedure library, such as the block size.

Attention: If a job that updates a procedure library is in a JES-managed job class group, and it is updating the procedure library used to start initiators, make sure that there is at least one initiator started before allowing the job to enter the system. Otherwise, a deadlock will occur; the procedure library used to start the initiator is disabled, the job is waiting for an initiator, and the initiator is waiting for the procedure library to be enabled. If this situation arises, the updating job must be canceled and resubmitted or a *RESTART,SETUP,jobno,CI command can be used to enable the procedure libraries (and let the initiator start) and restart the job through C/I processing. If a C/I FSS was active on a system that is no longer operational, enter the *S main,FLUSH command for that system. The command indicates that the C/I FSS is no longer active, so JES3 can immediately schedule the update job.

If a job that updates a procedure library is in a WLM-managed job class group, it is not necessary to check whether there is an initiator started before submitting the job. WLM-managed initiators are not started under JES3 and are not affected when a procedure library is disabled.

To prevent new jobs from updating the procedure library, change the DISABLE DSP maximum use count to 0 or issue the *F,X,D=DISABLE,HOLD command. To resume updating, increase the DSP maximum use count or issue the *F,X,D=DISABLE,RELEASE command.

Note: If you use the proclib update facility to move a procedure library to another volume, and the procedure libraries are allocated through the JCL statements in the JES3 cataloged start procedure, The JES3 local address spaces must be restarted in order to:

Reallocate the procedure library on the new volume. This is necessary if a JES3 local processor is a DSI candidate. Before a DSI is performed, all locals, which are DSI candidates must be restarted in order to pick up the change.
Vary offline the volume containing the old procedure library. During proclib update processing, the JES3 global and C/I FSS address spaces unallocate the procedure libraries being updated. However, the JES3 local address spaces do not unallocate the proclibs during proclib processing. This causes the VARY command for the proclib to fail when you attempt to vary the proclib offline to one of the local processors.

The JES3 local address spaces do not have to be restarted if the procedure libraries are defined through the DYNALLOC statements in the initialization stream.