Controlling the use of modules from the MVS link pack area

This topic describes what you must do to enable CICS® to use modules from the MVS link pack area, and what you can do to specify that CICS is not to use eligible modules from the MVS link pack area.

The methods for controlling the use of modules from the MVS link pack area do not apply to the modules DFHCSVC, DFHDSPEX, and DFHIRP. These modules can be used only from the MVS link pack area.

Modules in the MVS link pack area from hlq.SDFHAUTH

CICS uses standard MVS™ load facilities for modules installed in the MVS link pack area from the CICS APF-authorized library, hlq.SDFHAUTH. That is, such a module is used from the first of the following locations that it is found in:

  1. STEPLIB concatenation
  2. MVS link pack area
  3. MVS LNKLST

Using modules from the MVS link pack area

To use any of the CICS modules installed in the MVS link pack area from the hlq.SDFHAUTH library you must remove any version of the module from the hlq.SDFHAUTH library (or any other library in the STEPLIB concatenation).

Using modules from the STEPLIB

You can prevent CICS using modules installed in the MVS link pack area from the hlq.SDFHAUTH library by installing versions of those modules in a library in the STEPLIB concatenation. CICS then uses the versions of the modules from the STEPLIB concatenation into the CICS address space, rather than any versions that may be in the MVS link pack area.

Modules in the MVS link pack area from hlq.SDFHLOAD

The use of CICS modules installed in the MVS link pack area from the hlq.SDFHLOAD library is controlled by CICS system initialization parameters and resource definitions.

The hlq.SDFHLOAD library is used for non-nucleus CICS modules, and some CICS nucleus modules. You can also use the library for your own user application programs.

Using modules from the MVS link pack area

To use any of the CICS modules installed in the MVS link pack area from the hlq.SDFHLOAD library:

Notes:
  1. CICS uses eligible modules installed in the MVS link pack area, if:
    • You have not specified the name of the module on the CICS system initialization parameter PRVMOD.
    • The module has not been already loaded from the DFHRPL concatenation.
  2. If CICS cannot find an eligible module in the MVS link pack area, it loads the private (non-shared) version into the CICS address space from the DFHRPL concatenation, after issuing the message DFHLD0107I to warn you that the module is not in the MVS link pack area. (See topic The module-not-found warning message (DFHLD0107I) for more information about this message.)
  3. CICS assumes that the PL/1 modules, IBMBPSLA and IBMBPSMA, are installed in the MVS link pack area and issues message DFHLD0107I if it fails to find them there. If you want your PL/I application programs to run with the PL/I shared library facility, you must ensure that the modules IBMBPSLA and IBMBPSMA are installed in the MVS link pack area, or in the hlq.SDFHLOAD library (or another library in the CICS DFHRPL library concatenation).
  4. Program list tables (PLTs) must be placed in the DFHRPL concatenation. However, before PROGRAM resource definitions for phase one PLTPI programs and PLTSD programs are installed (for example, early in CICS initialization) CICS scans the MVS link pack area for those programs, and issues message DFHLD0107I if it cannot find such a program there.
  5. Likewise, before PROGRAM resource definitions for global and task-related user exit programs are installed (for example, early in CICS initialization) CICS scans the MVS link pack area for those programs, and issues message DFHLD0107I if it cannot find such a program there.
Specifying USELPACOPY(YES)

For every non-nucleus CICS module or user application program that you have moved to the MVS link pack area (that is, have removed from the DFHRPL concatenation), ensure that you have specified USELPACOPY(YES) on the associated PROGRAM resource definition. Otherwise, CICS isnot be able to find the module, and may fail to start up successfully.

Using modules from DFHRPL

You can prevent CICS using modules installed in the MVS link pack area from the hlq.SDFHLOAD library by either:

Verifying modules for the MVS link pack area

While verifying new versions of modules to be installed into the MVS link pack area, you can instruct a CICS region to use the new versions from the DFHRPL concatenation by any of the following options:

For further information about these options, see Using modules from DFHRPL

In all cases, you must install the new versions of the modules into the hlq.SDFHLOAD library, or another library in the DFHRPL concatenation.

If you are verifying many CICS LPA-eligible modules, you might like to add the hlq.SDFHLPA library to the DFHRPL concatenation. This allows you to check that the modules you have installed in the MVS link pack area are being loaded from there.

Note:
The CICS-supplied usermods use SMP/E to move CICS LPA-eligible modules into the hlq.SDFHLPA library. Similarly, if you use SMP/E to apply service to any of those modules, the versions in the hlq.SDFHLPA library is updated. The updated versions of the modules are used from the MVS link pack area after you next re-IPL your MVS with CLPA specified. Until then, if you add the hlq.SDFHLPA library to the DFHRPL concatenation of your CICS region, and specify that CICS is not to use the version of the modules in the MVS link pack area, the updated versions of the modules are used from the DFHRPL concatenation.

After you have installed and verified the use of modules from the MVS link pack area, you should remove the versions of the modules from the DFHRPL concatenation of your CICS startup job.

You can find out whether CICS is loading modules from the MVS link pack area or the DFHRPL concatenation by reviewing the index of a system dump for the CICS region started with the system initialization parameter LPA=YES. Modules loaded from the MVS link pack area have the dump option LD=3.

The module-not-found warning message (DFHLD0107I)

CICS issues message DFHLD0107I if it searches the MVS link pack area for a module installed there from hlq.SDFHLOAD and fails to find it.

If you encounter this message, check that you have specified USELPACOPY(YES) on the associated PROGRAM resource definition (if applicable). For further information about using modules loaded in the MVS link pack area from the hlq.SDFHLOAD library, see Modules in the MVS link pack area from hlq.SDFHLOAD.

CICS uses console routing code 11 for this particular message, which allows you to control the output of this message. For example, you can:

  1. Exclude, as required, routing code 11 from specific MVS console definitions in the CONSOLxx member of SYS1.PARMLIB.
  2. Use the MVS VARY command to prevent this message from appearing on specified consoles by omitting route code 11 from a VARY command that defines which routing codes go to specified devices. For example:
    VARY devnum,CONSOLE,ROUT=(rtcode,rtcode,.,.,.)

    Alternatively, you can remove route code 11 from those already defined by using the following VARY command:

    VARY devnum,CONSOLE,DROUT=(11)
  3. Use the MVS message processing facility (MPF) to inhibit the message. To use this facility, code an entry specifying the CICS message number in the MPFLSTxx member of SYS1.PARMLIB.

CICS assumes that the following PL/1 modules are LPA eligible and issues message DFHLD0107I if it fails to find them there:

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