IT35426: ON DB2/AIX, POST FROM THREAD_POST CAN BE SKIPPED/DEFERRED BY WAITER INTERRUPTED IN THREAD_WAIT , LEADING TO PANIC/SHUTDOWN

Db2 Version 11.1 Mod 4 Fix Pack 7 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• A timing hole in db2's synchronization implementation on AIX can
  lead to an abnormal shutdown when a waiter is interrupted by a
  force/signal.
  
  A variety of symptoms could occur, but one common symptom is an
  ESRCH error resulting in a panic.
  Eample db2diag.log entry :
  EDUID   : 5399                 EDUNAME: db2pfchr (TEST1) 0
  FUNCTION: DB2 UDB, SQO Latch Tracing,
  SQLO_SLATCH_CAS64::releaseConflict, probe:340
  CALLED  : OS, -, unspecified_system_function
  OSERR   : ESRCH (3) "No such process"
  DATA #1 : String, 13 bytes
  post error!:
  DATA #2 : File name, 16 bytes
  sqloLatchCAS64.C
  DATA #3 : Source file line number, 8 bytes
  1089
  DATA #4 : Codepath, 8 bytes
  2:6:8:20:22:26
  DATA #5 : String, 126 bytes
  0x0000000004010000: {
     held X: 1
     reserved for X: 0
     shared holders: 0
     firstSharIndex: 0x40
     firstExclIndex: 0x0
  
  example stack
  sqle_panic__Fi
  dumpDiagInfoAndPanic__17SQLO_SLATCH_CAS64CFCPCcCUiCUlT3ClT3CiT1T
  3T7
  releaseConflict__17SQLO_SLATCH_CAS64Fv
  sqlbReadAndReleaseBuffers__FP16SQLB_OBJECT_DESCUiUlN23P11SQLB_pf
  Misc
  
  demangled:
  sqle_panic
  SQLO_SLATCH_CAS64::dumpDiagInfoAndPanic
  SQLO_SLATCH_CAS64::releaseConflict
  sqlbReadAndReleaseBuffers
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * all                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to 11.1.4.7                                          *
  ****************************************************************
  

Problem conclusion

• Upgrade to 11.1.4.7
  

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:

  IT37537

Fix information

• Fixed component name

  DB2 FOR LUW

• Fixed component ID

  DB2FORLUW

Applicable component levels

• RB10 PSN

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