To use the CICS® interface to JES, you must define the
DFHSIT SPOOL=YES system intialization parameter in your CICS startup JCL.
You must specify RESP or NOHANDLE on the EXEC CICS SPOOLCLOSE, SPOOLOPEN, SPOOLREAD, and SPOOLWRITE commands.
RESP bears a one-to-one correspondence with HANDLE CONDITION. If you do not
code RESP, your program abends. You can also code the RESP2 option.
Transactions that process SYSOUT data sets larger than 1000 records, either
for INPUT or for OUTPUT, are likely to have a performance impact on the rest
of CICS. When you cannot avoid such a transaction, you should carefully evaluate
general system performance. You should introduce a pacing mechanism if the
effects on the rest of CICS are unacceptable.
All access to a JES spool file must be completed within one logical unit
of work. Issuing an EXEC CICS SYNCPOINT command implicitly issues a SPOOLCLOSE
command for any open report.
There are internal limits in JES that you should consider when you are
designing applications. Some apply to JES2, some to JES3 and some to both.
In particular:
- JES2 imposes an upper limit on the total number of spool files that a
single job (such as CICS) can create. If CICS exceeds this limit during its
execution, subsequent SPOOLOPEN OUTPUT commands
fail with the ALLOCERR condition.
- JES3 does not impose such a limit explicitly, but for both JES2 and JES3,
some control information for each file created persists for the entire execution
of CICS. For this reason, creating very large numbers of spool files can stress
JES resources; you should consult your system programmer before designing
such an application.
- Spool files require other resources (buffers, queue elements, disk space)
until they are processed. You need to consult your systems staff if you are
producing very large files or files that may wait a long time for processing
at their destinations.
- Code NODE('*') and USERID('*') if you want to specify the local spool
file and to enable the OUTDESCR operand to override the NODE and USERID operands.
Do not use NODE('*') with any other userid. If the NODE and USERID operands
specify explicit identifiers, the OUTDESCR operands cannot override them.
- Ensure that your system is defined so that data sets produced by CICS
are not in HELD status in JES. CICS does not search for data sets in HELD
status when the EXEC CICS SPOOLOPEN INPUT command is issued.
[[ Contents Previous Page | Next Page Index ]]