IT19023: AFTER CRASH RECOVERY, AN DEFERRED ONLINE REORG CLEANUP MIGHT CAUSE AN X ROW LOCK MISSING FOR AN INDOUBT TRANSACTION.

DB2 Version 11.1 Mod1 Fix Pack1 iFix001 for Linux, UNIX, and Windows
DB2 Version 11.1 Mod 2 Fix Pack 2 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod2 Fix Pack2 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod2 Fix Pack2 iFix002 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix002 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod4 Fix Pack4 iFix001 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• If there was a database outage due to hardware or software
  failure, and at the time of the outage there was an online reorg
  (OLR) running and there was an indoubt transaction modifying the
  same table that is being reorganized, there is a chance that the
  inodubt transaction modified a row that is also being considered
  by OLR.  After crash recovery, the database is open for new
  connections.  Locks should be reacquired data changed by the
  indoubt transaction.  There is a chance that one of the row
  modified by the indoubt transaction is not reacquired.  Instead,
  the unfinished OLR acquired an NS lock on that row.  Queries
  from new connections might be able to see this row, before the
  indoubt transaction is resolved.
  
  One can find the existence of deferred OLR after crash recovery
  by the following message in db2diag.log:
  
  2017-01-29-20.50.46.579355-300 I16657073E525         LEVEL: Info
  PID     : 4278                 TID : 140077770467072 KTID : 4879
  PROC    : db2sysc
  INSTANCE: rzheng               NODE : 000            DB   :
  REORGDB
  APPHDL  : 0-21                 APPID: *LOCAL.DB2.170130015058
  HOSTNAME: hotellnx118
  EDUID   : 83                   EDUNAME: db2reorg (REORGDB)
  FUNCTION: DB2 UDB, data management,
  sqldOLRCleanupAfterCrashRecovery, probe:5701
  DATA #1 : <preformatted>
  Starting ONLINE REORG cleanup (2;3), TID=0000000000000E84.
  
  One can find the existence of indoubt transaction via the
  following :
  
  2017-01-29-20.50.45.359106-300 I16653970E594         LEVEL: Info
  PID     : 4278                 TID : 140081482426112 KTID : 4302
  PROC    : db2sysc
  INSTANCE: rzheng               NODE : 000            DB   :
  REORGDB
  APPHDL  : 0-7                  APPID: *LOCAL.rzheng.170130014954
  AUTHID  : RZHENG               HOSTNAME: hotellnx118
  EDUID   : 18                   EDUNAME: db2agent (REORGDB)
  FUNCTION: DB2 UDB, recovery manager, sqlpresr, probe:3280
  DATA #1 : <preformatted>
  Incomplete trasnsactions (either in-doubt or deferred rolllback)
  exist at the end of crash recovery on log stream 0.
  
  But there is no good way to know if the indoubt transaction
  affected the same table as OLR, and more specifically affected
  the same row that OLR might be processing.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ALL                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to DB2 11.1 Mod1 Fix Pack 1 iFix001                  *
  ****************************************************************
  

Problem conclusion

• First fixed in DB2 11.1 Mod1 Fix Pack 1 iFix001
  

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:

Fix information

• Fixed component name

  DB2 FOR LUW

• Fixed component ID

  DB2FORLUW

Applicable component levels