Creating extra sets of CICS Transaction Server target libraries (optional)

You can use the CICS® Transaction Server installation job, DFHISTAR, to generate an optional installation job, DFHINSTA, which you can use to create extra copies of the CICS Transaction Server target libraries and UNIX System Services directories.

About this task

What are the benefits of using multiple libraries
  • Backing out PTFs and APARs. If you apply PTFs or APARs to CICS Transaction Server and if they fail a fix-test, you can back out the changes with minimum disruption.
  • DASD failure. Multiple libraries protect you against failure of the DASD on which the CICS Transaction Server load libraries reside.
What are the factors you should consider when making the decision to use multiple libraries
  • Your requirement for high availability. As already stated, the use of multiple libraries can protect you against CICS Transaction Server downtime caused by DASD failure or incorrect service, either from IBM-supplied PTFs or from your own modifications to your CICS Transaction Server region.
  • The extra DASD required. Multiple libraries require more disk space.
  • Other ways of providing high availability. For example, use a CICSPlex®, z/OS® Communications Server persistent sessions, and MVS™ functions to provide restart of CICS Transaction Server regions.
  • The added complexity of maintaining multiple sets of CICS Transaction Server libraries. Two or more sets of CICS Transaction Server target libraries, together with the SMP/E procedures that are required to support them, increase the complexity of maintenance. Define procedures to ensure that upgrades to the CICS Transaction Server libraries are kept under control.
  • Alternative solutions. If you have already established a proven process for fix verification and for testing applications developed for your production CICS Transaction Server region, you might decide that you do not require multiple CICS Transaction Server libraries.

You can use the DFHINSTA job, generated by the DFHISTAR job, to create extra sets of CICS Transaction Server target libraries fully under the control of SMP/E. Each time you run the DFHINSTA job, you can generate only one extra set of target libraries.

To create an extra sets of target libraries, complete the following procedure. You can repeat the steps to create more sets of target libraries.

Procedure

  1. Edit the DFHISTAR job to specify values:
    • The ADDTVOL, AINDEX, ASMPSCDS, AZONE, AZONECSI, AZONELOG, and USSDIRA parameters, for the new set of target libraries.
    • The INDEX, TZONE, TZONECSI, and TZONELOG parameters, for the primary target libraries you want to copy from. The TZONE, TZONECSI, and TZONELOG parameters must specify the target zone that contains the CICS Transaction Server target libraries defined with the high-level qualifier provided by the INDEX parameter.
    • The DZONE, DZONECSI, and DZONELOG parameters, for the distribution libraries to be associated with the new set of target libraries.

    For further information about editing the DFHISTAR job and about the parameters of the DFHISTAR job, see Editing the DFHISTAR job. Do not change the other parameters in the DFHISTAR job.

  2. Submit the DFHISTAR job.

    When you run the DFHISTAR job, it saves the generated version of the DFHINSTA job in the CICSTS54.XDFHINST library with the member name specified on the SELECT parameter in the DFHISTAR job. The LIB parameter of the DFHISTAR job specifies the data set name of the CICSTS54.XDFHINST library.

  3. Consider running the DFHIHFSA job.
    If you decide to create an additional SMP/E target zone using job DFHINSTA, run the DFHIHFSA job before running the DFHINSTA job. DFHIHFSA creates an additional SMP/E target zone for z/OS UNIX.
    This job performs the following steps:
    • Unmounts the z/OS UNIX file system at directory /pathprefix/usr/lpp/cicsts/ussdir to allow the job to rerun and, if necessary, forces return code 0.
    • Deletes the /ussdira directory at /pathprefix/usr/lpp/cicsts, where ussdira is the name of the directory specified on the ussdira parameter in the DFHISTAR job. This allows the job to rerun and, if necessary, forces return code 0.
    • Deletes the file system specified in the HFSADSN parameter of the DFHISTAR job to allow the job to rerun and, if necessary, forces return code 0.
    • Creates the file system specified in the HFSADSN parameter of the DFHISTAR job.
    • Creates the /ussdira directory at /pathprefix/usr/lpp/cicsts, where ussdira is the name of the directory specified in the ussdira parameter in the DFHISTAR job.
    • Mounts the file system at directory /pathprefix/usr/lpp/cicsts/ussdira
    • Creates the dfhconfig directory at /pathprefix/usr/lpp/cicsts/ussdira.
    • Creates empty files featuretoggle.properties and groupfeaturetoggle.properties in the dfhconfig directory.
    • Changes the permission settings for the ussdira directory and the ussdira/dfhconfig directory to 775.

    All steps of this job must end with return code zero for the job to be successful.

    CICS requires the MOUNT issued by DFHIHFSA to access files stored in the z/OS UNIX, but the MOUNT command is lost when you re-IPL MVS. SDFHINST member DFHBPXPA contains a MOUNT command for @pathprefix@/uss_path_a@ where where uss_path_a is the name of the directory specified in the uss_path parameter in the DFHISTAR job. Copy this command into a BPXPRMxx member of the SYS1.PARMLIB data set to ensure that the mount is restored when MVS is IPLed.

  4. Submit DFHINSTA.

    The DFHINSTA job, or a copy of it, copies the CICS Transaction Server target libraries specified by the INDEX parameter, and creates corresponding CICS Transaction Server SMP/E data sets for them. In particular, it allocates a new SMP/E CSI data set for the extra target zone.

    So that you can run the DFHINSTA job more than once, step 1 deletes previous copies of the data sets to be created. Step 3 deletes the SMP/E CSI data set. Step 6 removes the ZONEINDEX entry for the extra target zone.

    The first time the DFHINSTA job is run it will fail with return code 8, and step 6 will give the following messages: 
         GIM35701E ** ZINDEX SUBENTRY azone WAS NOT DELETED BECAUSE
                       IT DOES NOT EXIST.
     GIM25601I    THE SPECIFIED ENTRY WAS NOT UPDATED BECAUSE OF
                       AN ERROR DURING UCLIN PROCESSING.

    You can ignore these messages the first time the job is run.