If you are using CICS Transaction Server for z/OS V4.2 with IMS V12, you should apply the IMS PTF for HIPER APAR PM60830. This APAR resolves a performance regression or degradation problem that can occur when upgrading from IMS V11 to V12 and running CICS-IMS quasirent applications. PM60830 should also improve performance if you are making your CICS-IMS applications threadsafe.
Apply PTF UK81843 for IMS V12 APAR PM60830 to benefit from performance improvements when running CICS TS V4.2 with IMS V12. The same performance improvements should be seen with CICS TS V5.1.
Following are highlights from testing done at IBM that show performance improvements when comparing CICS TS V4.2 with IMS V11 running a quasirent application to CICS TS V4.2 with IMS V12 running a threadsafe application.
- 31.36% improvement in external throughput rate (ETR) or transactions per second
- 6.78% improvement in efficiency or internal throughput rate (ITR = ETR divided by CPU% busy)
- 43.33% reduction in transaction response time
- 5.89% reduction in CICS service time per transaction
These results indicate that if you are enabling your CICS IMS applications to use the open transaction environment (OTE) through threadsafe programming that there are some great benefits to running CICS TS V4.2 with IMS V12. However, as with any workload, performance results can vary. Therefore, studies should be run for your specific environment and application mixes.
IBM plans to make the complete report from testing available in late November on the "White papers" section of the IMS Library page.
For additional APARs that you should apply if running CICS TS V4.2 with IMS V12, you should refer to DFHDB8222 Connection from CICS TS 4.2 to IMS fails. DBCTL return code is 36 and APAR PM67188.
CICS/TS CICS TS CICS Transaction Server