OA43280: HANG DURING SUBSYSTEM TERMINATION DUE TO DEADLOCK IN END OF TASK 14/04/29 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• During termination of a registered subsystem, (such as CICS) EOT
  may get hung waiting on a subsystem latch. If EOT is called
  again, the two may get hung up together due to the way the
  latches are handled. Hang is between the UAAB and subsystem
  latch.
  
  The typical scenario involves a CANCEL shortly after a CICS
  SHUTDOWN IMMEDIATE. The shutdown immediate generates an EOT
  thread, and then the later cancel also causes EOT. These two
  threads get hung up while processing through open ACBs. If the
  region has many open data sets during shutdown, the window is
  expanded.
  
  Symptoms are a hang in during termination of a CICS region, and
  the D SMS,SMSVSAM,DIAG(C) may show contention on multiple
  latches.
  
  Problem was introduced by serialization changes in OA37889.
  Please review both carefully to assess exposure before removing
  PTFs for OA37889.
  
  Additional keywords:
  UAAB IDAUAAB IDASSYS IDAVSEOS
  

Local fix

• Avoid multiple cancels to a registered subsystem (such as CICS)
  Closing all open ACBs prior to CICS shutdown will also reduce
  the exposure.
  If you hit the hang, restarting SMSVSAM will free the
  contention. FORCE on the CICS region will also free a single
  region, but the hang in SMSVSAM will persist until next restart.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All VSAM RLS users who plans on shutting     *
  *                 down their CICS region.                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: While shutting down the CICS region,    *
  *                      a hang might occur due to multiple tcbs *
  *                      all going through End of Task and       *
  *                      competing for the same resources.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  SMSVSAM End of Task processing might results in a hang
  due to multiple tcbs all ending simultaneously. The
  serialization of End of Task requires many resources
  to be obtained in a correct order. If any one of the
  tcb obtained one resource in an incorrect order then
  a hang will occur during End of Task processing.
  

Problem conclusion

• SMSVSAM End of Task processing was modified to
  correct the order of the resources that needs to be
  obtained.
   KEYWORDS: RLSPSP/K
  

Temporary fix

• *********
  * HIPER *  AA43280
  *********
  

Comments

• ×**** PE14/03/10 FIX IN ERROR. SEE APAR OA44707  FOR DESCRIPTION
  

APAR Information

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

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

  UA72206 OA44397 UA72142

Modules/Macros

• IDAVSEOS
  

Fix information

• Fixed component name

  VSAM REC LEV SH

• Fixed component ID

  5695DF122

Applicable component levels

• RD10 PSY UA72142

     UP14/02/25 P F402 ­

• R210 PSY UA72206

     UP14/02/25 P F402 ­

Fix is available

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