LI73140: REORG FAILURE FOLLOWED BY DROPPING OF TEMP TABLESAPCE CAN CAUSE CRASH RECOVERY TRAP DUE TO REORG LOG RECORD FALLING IN CR WINDOW

APAR status

• Closed as program error.

Error description

• Scenario
  
  Temp tablespace created.  One or more reorgs are started using
  this temp tablespace and then subsequently interrupted.  Temp
  tablespace being used by reorgs is dropped.  Operating System
  shutdown/crash occurs which results in DB2 being abnormally
  shutdown.  Restart system and DB2.  Connect to database or
  activate database results in crash recovery . The reorg log
  records are within the recovery window and are replayed.
  References to the now deleted tablespace result in internals of
  DB2 using invalid pointers and a crash occurs during recovery.
  
  
  Avoidance
  
  In order to avoid the recovery crash it is necessary to remove
  the reorg log records from the recovery window.  In order to do
  this, the minBuffLSN (oldest committed transaction not yet
  hardened to disk and is the starting point for recovery) must be
  set past the last reorg log record Log Sequence Number.  The Log
  File Header itself then needs to be hardened to disk .
  
  To accomplish this , the following steps can be peformed :
  
  connect to db
  db2 create tablespace temp
  start reorgs
  reorgs are interrupted
  db2 force applications all (this will force all connection to be
  torn down at the server and force rollback of all inflight
  transactions)
  db2 deactivate db <dbname> (this will force log file closure and
  flush the log file header to disk).
  db2 connect to db
  db2 drop tablespace temp
  
  If a DB2 crash occurs at this point then reorg log records will
  not be within the recovery window and would therefore not be
  replayed and therefore the recovery crash would be avoided.
  

Local fix

• Once the problem is hit no workaround. However, the situation
  could be avoided as described in this APAR
  

Problem summary

• Users affected: User intrrupts reorg and then stops the
  instance abruptly
  
  Problem Description: Please  see APAR  ERROR DESCRIPTION
  
  Problem Summary: Interruption of reorg followed by dropping
  of temp tablespace can cause crash recovery failure after
  an abrupt instance failure
  

Problem conclusion

• First fixed in DB2 UDB Version V8, FixPak 17
  (CMVC defect#379406)
  

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:

  LI73141 LI73142

Fix information

• Fixed component name

  DB2 UDE ESE LIN

• Fixed component ID

  5765F4104

Applicable component levels

• R820 PSY

     UP