IBM Support

High CPU utilization in CICS region with IAM

Question & Answer


Question

Why has the CPU consumption increased by over 100% in the past 10 days in my CICS Transaction Server for z/OS (CICS TS) region? This region is now being cycled on a weekly basis when previously it was cycled daily. I have a dump taken when CPU usage was 100%.

I am using INNOVATION ACCESS METHOD (IAM) from INNOVATION DATA PROCESSING.

Answer

Looking at the system dump, enter command SYSTRACE PERFORDATA from IPCS option 6).

In the CPU breakdown by ASID, the TCB Adr 009CC4D8 stood out as taking a lot of CPU time:

 ASID Jobname   TCB Adr  # of DSPs     Time 
 0184 <cicsjob> 009C9E88        6     0.000170        
 0184 <cicsjob> 009BD488       24     0.000874        
 0184 <cicsjob> 009CC4D8      772     0.154085 <<<<<   
                                    ------------           
                                      0.155131   

and the 'Interrupt PSW' D2BDCCB0 (or 52BDCCB0) for TCB Adr 009CC4D8 shows a Count of 574 times!

 SRB/TCB  IASN   Interrupt PSW     Count     
 -------- ---- -------- --------  --------   
 009CC4D8 0184  078D2000 D2BDCCB0      574  

Next, enter option 1 from the IPCS primary option menu to Browse the dump data set starting at the 'Interrupt PSW' address then scroll backwards until you find the eyecatcher of the failing module. In this case, the 'Interrupt PSW' D2BDCCB0 (or 52BDCCB0) is pointing to module IAMACCXM at offset 2F18. The eyecatcher for IAM module IAMACCXM contains a date of 6/1/73 ver 9.1/01P .¢09.0:

 52BD9D98   e         .02..03m e
 52BD9DA0   e .03..03*.03....q e
 52BD9DB0   e ...q..w?..x....d e
 52BD9DC0   e .IAMACCXMPROPRIE e
 52BD9DD0   e TARY CODE INNOVA e
 52BD9DE0   e TION DATA PROCES e
 52BD9DF0   e SING 6/1/73 -- V e
 52BD9E00   e ER.9.1/01P .!09. e

The IAM fix for this problem is Zap ID p-91.0105. Contact INNOVATION DATA PROCESSING for IAM Support if you need additional assistance.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Platform":[{"code":"PF035","label":"z\/OS"}],"Component":"Performance","Version":"","Line of Business":{"code":"LOB17","label":"Mainframe TPS"}}]

Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
18 September 2018

UID

dwa1448178