OA54179: ABEND026 RSN0C1C1026 WHEN CHANNEL PATH DECONFIGURED 17/10/18 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Deconfiguring a coupling facility (CF) channel path while a
  request is in flight can cause the request to fail with an
  indeterminate result, when it should be restarted on another
  path.  The inappropriate request completion can result in any of
  the following errors:
  
  ABEND026 RSN0C1C1026
  ABEND026 RSN09260004
  ABEND026 RSN0CA80001
  
  The impact on the CF-exploiting application that initiated the
  request is unpredictable.  It may recover, or it may fail in
  response to the unexpected request completion result.
  
  PE Information:
  
  Users Affected:
  
  OA47796 PTF UA82981
  All installations using CF structures with the specified PTF
  applied.
  
  User Impact:
  
  APAR OA47796 provided the intended new function but introduced a
  new problem.  APAR OA47796 introduced an asynchronous
  system-managed duplexing protocol for lock structures to improve
  duplexing performance.  However, associated changes to
  subchannel recovery processing introduced an error that affects
  commands initiated on a subchannel that is removed from the
  configuration while the command is in flight.  Such a command
  will incorrectly complete with a return code indicating an
  unknown component error rather than being restarted on another
  subchannel.  The unexpected return code may cause unpredictable
  application failures.
  
  Local Fix:
  
  Avoid dynamic path or CF configuration changes that cause the
  removal of a subchannel from the configuration while CF
  workloads are active.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Installations exploiting parallel sysplex                    *
  * at zOS V2R2 (HBB77A0) with the PTF for                       *
  * OA47796 installed, or at zOS V2R3                            *
  * (HBB77B0).                                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ABENDS026 RSN0C1C1026 when channel                           *
  * path deconfigured.                                           *
  *                                                              *
  * SYSPLEXDS                                                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Install the applicable PTF on each system                    *
  * in the sysplex.  A rolling IPL is                            *
  * sufficient to activate the fix.                              *
  ****************************************************************
  Deconfiguring a coupling facility (CF) channel path while a
  request is in flight can cause the request to fail with a
  result indicating an internal error, when it should recover or
  restart on another path.  The inappropriate request completion
  can result in any of the following errors:
  
  ABEND026 RSN0C1C1026
  ABEND026 RSN09260004
  ABEND026 RSN0CA80001
  
  The impact on the CF-exploiting application that initiated the
  request is unpredictable.  It may recover, or it may fail in
  response to the unexpected request completion result.  A
  duplexed structure may fail due to inconsistent results.
  

Problem conclusion

• Corrected subchannel recovery processing for requests being
  processed on a subchannel associated with a deconfigured path.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UA94319 UA94320

Modules/Macros

• IXLE1REC
  

Fix information

• Fixed component name

  CROSS SYS.EXT.S

• Fixed component ID

  5752SCIXL

Applicable component levels

• R7B0 PSY UA94319

     UP17/11/22 P F711 ­

• R7A0 PSY UA94320

     UP17/11/22 P F711 ­

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.