Configuration Best Practices › Tuning for Improved Performance and Lower TCO › Utilize the IBM z Integrated Information Processor

Utilize the IBM z Integrated Information Processor

The zIIP (IBM System z Integrated Information Processor) is a specialty mainframe processor designed to help free general computing capacity from the Central Processor (CP). CA IDMS exploits the zIIP to provide improved Total Cost of Ownership (TCO) for your mainframe environment.

You can easily evaluate the benefit of the CA IDMS zIIP exploitation feature for your environment.

• If you have one or more zIIPs available to the LPAR on which your CA IDMS central version is executing, specify ZIIP=Y as a CA IDMS startup parameter.
• If no physical zIIP is present, you can also estimate potential zIIP redirection by specifying ZIIP=Y at startup.

  Note: Running with ZIIP=Y on a system without a ZIIP engine can result in performance overhead and inaccurate estimates.

In both cases, you can then use CA IDMS system statistics to calculate the actual or potential CP utilization reduction for your environment.

Note: The zIIP exploitation feature was introduced with CA IDMS r17 and enhanced for Version 18.

Business Value:

Use of the zIIP feature can help you lower your TCO (total cost of ownership) on the mainframe. By exploiting zIIP, CA IDMS can help you deliver more computing capacity and throughput without additional system hardware resources.

CA IDMS makes wide use of the zIIP engine. Portions of all typical CA IDMS production workloads—including those generated by online transaction systems, batch processing jobs, and distributed platform requests—can exploit zIIP capacity to offload processing that would otherwise occur on the Central Processor (CP). Because significant portions of all these workloads can run on zIIPs, you can leverage zIIP capacity to scale your database environments without incurring expensive hardware upgrades.

The best results—as measured by percentage of CP processing offloaded to the zIIP and the amount of white space created on the CP—were found with batch/CV processing, CICS/DML requests, JDBC and ODBC distributed requests, CA IDMS/DDS requests, and any kind of external request processing to the database engine. A system architected with CA IDMS application-owning regions (AOR) making requests to CA IDMS database-owning regions (DOR) may also see significant benefits. CA IDMS/DC and CA ADS online applications that execute in the same CA IDMS region as the database will see less benefit because user mode code is not eligible for zIIP execution and cannot be offloaded. Overall results range from a benefit of 10% to 50%. Your actual benefit may vary depending on your mix of CA IDMS work—online, batch, CICS, CA ADS, COBOL, Web, JDBC, ODBC, CA IDMS/DDS, and so on.

Additional Considerations:

Most CA IDMS system code is eligible to run on a zIIP processor. CA IDMS runtime processing ensures that a non-zIIP processor is selected to run non-eligible routines, such as user exits, database procedures, SQL-invoked routines, and application programs.

To implement zIIP support for your system, take the following steps:

1. Ensure z/OS software feature HBB7709 is available on your system.
2. Provide the ZIIP=Y startup parameter in the central version startup JCL.
3. Make sure the specific rules for load module residence for zIIP processing are met:
   • The central version startup routine, typically RHDCOMVS, should reside in an authorized library in the STEPLIB concatenation. It can reside in a linklist library, but this is not recommended.
   • CA IDMS nucleus modules, including all line drivers and service drivers, must be loaded from an authorized load library in the CDMSLIB concatenation or from the Link Pack Area (LPA). The IBM Language Environment library (usually CEE.SCEERUN) must be authorized if it is included in the CDMSLIB concatenation. Alternatively, the following modules must reside in the LPA: CEEPIPI, CEEPLPKA, and CEEEV003.
   • z/OS Callable Services library (SYS1.CSSLIB) must be in the linklist or it must be authorized and included in the STEPLIB concatenation.
   • Modules that consist of non-executable code or code that is never eligible to run on a zIIP processor do not have to come from a secured location. Most modules that are supplied by a client or that are modifiable at a client site are in this category.

More Information:

For additional information about utilizing zIIPs and using statistics to evaluate the CP utilization reduction, see the ZIIP Exploitation section in the CA IDMS System Operations Guide.