Configuration Best Practices › Tuning for Improved Performance and Lower TCO › Configure Your CICS Environment

Configure Your CICS Environment

The IBM CICS Transaction Server (CICS TS) product can be used as a front-end TP monitor with back-end CA IDMS central versions in multiple ways. The two most common ways are listed here:

• Use CICS TS as the online application program execution environment and access CA IDMS only for database services. This type of usage requires assembling the CICSOPT macro to create an IDMSINTC module. The CA IDMS CICS interface program IDMSINTC is created by assembling the CICSOPT macro and linking it as described in the CA IDMS System Operations Guide.
• Use the CA IDMS/UCF product with CICS TS to enable CICS terminals to access online application programs that execute in the CA IDMS/DC environment. In addition to creating an IDMSINTC module, this type of usage also requires assembling the #UCFCICS macro. The CA IDMS/UCF front-end module UCFCICS is created by assembling the #UCFCICS macro with other macros and linking the resulting object modules as described in the CA IDMS System Operations Guide.

When new features are introduced for a new CA IDMS release, the default values for the CICSOPT and #UCFCICS macros are set so that the new features are not enabled. This ensures that customers using the default values will not encounter unexpected results when they upgrade to a new release. As a result, however, there are cases where the recommended best practice differs from the default setting.

The following best practices apply when configuring CICS TS for use with CA IDMS:

• Set the TPNAME parameter of the CICSOPT macro to null or blanks and modify the CICS TS System Initialization Table (SIT) for each CICS region accessing the same CA IDMS system to have a unique SYSIDENT value.

  Business Value:

  Multiple CICS regions can use the same IDMSINTC load module to access the same CA IDMS back-end system. This best practice facilitates the setup and maintenance for customers that have multiple CICS regions that access the same CA IDMS central version. This improves DBA productivity and provides for consistent CICS TS usage with CA IDMS. It enables additional CICS regions to be easily added if there is increased workload for CA IDMS processing.

  Additional Considerations:

  In addition to coding the CICSOPT TPNAME parameter value as null or blanks, you must also modify the CICS TS System Initialization Table (SIT) for each CICS region to ensure that each region has a unique SYSIDENT value. When the CICSOPT TPNAME parameter is null or blanks, then the IDMSINTC interface will use the SYSIDENT of the CICS region as a unique identifier.

  The alternative is to have multiple CICS regions that use the same SYSIDENT value accessing the same CA IDMS region. In this case, each CICS region must have its own IDMSINTC interface created by coding a CICSOPT macro with a unique TPNAME value. This creates more setup work for the DBA and requires more work to consistently maintain each IDMSINTC module.

  More Information:

  For more information about the CICS TS SIT parameters, see the appropriate IBM documentation. For more information about the CICSOPT parameters, see the CA IDMS System Operations Guide.

• Use the SYSCTL DDNAME parameter of the CICSOPT macro instead of the SVC and CVNUM parameters to specify the CA IDMS system to access.

  Business Value:

  If the same CICS region is used to access multiple CA IDMS backend systems, then a separate IDMSINTC interface module must be created for each unique CA IDMS central version. By using this best practice, the name of the CA IDMS system to be accessed can be controlled at runtime. This provides for flexibility and enables a customer to respond quickly to changes in system workloads by bringing up additional CA IDMS back-end systems.

  Additional Information:

  The CICS TS startup JCL must include a ddname that matches the CICSOPT SYSCTL DDNAME parameter. It must point to the same dataset as the one specified in the SYSCTL DD statement in the CA IDMS system startup JCL.

  More Information:

  For more information about the CICSOPT parameters, see the CA IDMS System Operations Guide.

• Use the USERCHK parameter on the #UCFCICS macro and require each user to sign on to CICS TS.

  Business Value:

  Using this best practice provides enhanced security. If a UCF session terminates abnormally, a subsequent user will not inadvertently gain access to the information from the previous user's session.

  Additional Information:

  Use CICS TS installation security to require each user to sign on to CICS TS.

  More Information:

  For more information about CICS TS security, see the appropriate IBM documentation. For more information about #UCFCICS parameters, see the CA IDMS System Operations Guide.