These additional considerations apply to a started task that runs
under the master subsystem:
- Any started task that can operate under the master subsystem can
also run under the primary JES subsystem.
- A started task running under the master subsystem (SUB=MSTR) may
choose to use JES services. To do so, the task must issue a Request
Job ID call to the JES. (See z/OS MVS Using the Subsystem Interface for additional information about the Request Job ID call.)
- The started task may include JES statements and commands with
the // COMMAND statement. Note, however, that if JES is not running,
the system may queue or purge these statements.
- The JCL may not include a JCLLIB statement.
- The JCL may include PROC and PEND statements if the JCL is a procedure,
but not if it is a job.
- The started task may not have SYSIN data sets.
- The system will initially allocate only data sets
that are cataloged in the master catalog or a user catalog. Catalogs
must reside on online volumes.
- You may dynamically allocate data sets that are not cataloged
in the master catalog to a task running under the master subsystem
- You may dynamically allocate SYSOUT data sets after successfully
completing a Request Job ID SSI call.
- JES exits do not get control during startup processing of a started
task. If, however, the started task issues a Request Job ID SSI call,
JES exits will get control for the minimal JCL used to construct the
JES job structure.
- SMF exits, such as IEFUJV, get control with the subsystem shown
- SRM determines performance characteristics based on the master
- You may not specify JES3-managed devices in the procedure; JES3
cannot manage devices for tasks that run under the master subsystem.
- You must code a TIME= value on the EXEC statement of the procedure
(such as TIME=NOLIMIT), or else specify the program as a system task
in the program properties table (PPT). Otherwise, the task will end
abnormally with a time-out condition.
- You must specify the region size that will be used if REGION is
not specified in the JCL.