PH37104: Progressively worse performance over time in an IMS Java Message Processing (JMP) region with CANCEL_PGM=Y

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Although CANCELing COBOL programs is not typically a problem in
  single-threaded batch environments, the frequent CANCELing of
  programs in a multi-threaded environment leads to a performance
  problem.
  

Local fix

• Recycle the IMS region.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL V5                 *
  *                 and later releases running programs under a  *
  *                 multi-threading environment and doing a      *
  *                 large number of program CANCEL. Programs     *
  *                 interoperating with Java, or calling the C   *
  *                 pthread library functions directly or        *
  *                 indirectly, are multi-threading.             *
  ****************************************************************
  * PROBLEM DESCRIPTION: High CPU usage in COBOL runtime library *
  *                      CSECT IGZCEVR.                          *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  ****************************************************************
  When running under multi-threading, control areas belonging to
  canceled COBOL programs are not properly reused. As the number
  of these freed areas grows, they interfere with the logic in
  initializing other new COBOL programs, leading to excessive CPU
  usage. This also causes more storage consumption, but the effect
  is less noticeable than performance.
  
  COB0501T/K COB0502T/K COB0601T/K COB0602T/K COB0603T/K
  

Problem conclusion

• The error in the COBOL runtime library in handling
  program control area free and reuse has been fixed.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI75919 UI75920

Modules/Macros

• IGZCEV4  IGZCMGEN IGZCMGUE IGZLLIBV IGZXAPI  IGZXCDA  IGZXD24
  IGZXDMR  IGZXJNI2 IGZXLPIO IGZXLPKA IGZXLPKB IGZXLPKC IGZXLPKD
  IGZXLPKE IGZXLPKF IGZXLPKG IGZXPK2
  

Fix information

• Fixed component name

  LE ENT COBOL LI

• Fixed component ID

  568819812

Applicable component levels

• R7B0 PSY UI75919

     UP21/06/24 P F106

• R7C0 PSY UI75920

     UP21/06/24 P F106

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.