DB2 FOR LUW / DB2FORLUW / A50 - DB2

A timing window exists between three applications that could 
result in a dead latch.  In order for the this to materialize 
the 
following things must happen: 
- A range-partitioned table exists with multiple ranges, where 
each range has at least one partitioned index. 
- At least two of the partitioned indexes in the table have 
indexes that were marked invalid and require index recreation to 
rebuild them. 
- Both partitioned indexes that are marked invalid must be 
defined in the same table space. 
- Two separate applications must drive index recreation for each 
invalid index above. 
- A third application has to be running the LOAD utility.  The 
LOAD utility can be for another table, as long as it shares the 
same table space as the table space used for the partitioned 
indexes above. 
- The LOAD utility must be using the 'COPY NO' option 
- The connection for the LOAD utility must be using LOCK TIMEOUT 
set to 
infinite 
 
This dead latch can be detected by analyzing a combination of 
the 
lock monitoring, db2pd -latches and db2pd -stack output. 
 
The three applications will be holding and requesting the 
resources in the following states: 
 
1) First index recreate 
 Holding latch type identified by 
SQLO_LT_SQLD_TCB_LOTCH__tcbIndexValidityLotch 
 Waiting for the table space lock.  Requesting the lock in IX 
mode. 
 
2) LOAD 
 Waiting for the table space lock.  Requesting the lock in U 
mode. 
 
 A snippet of the stack while it is waiting, which can be 
generated with db2pd -stack: 
  _ZN8sqeAgent14IntrptWaitLock 
  _Z18sqleIntrptWaitLock 
  _Z21sqlplWaitForLockGrantP9sqeBsuEdu 
  _Z13sqlplWaitOnWP 
  _Z21sqlplMakeNewRequestSD 
  _Z19sqlplMakeNewRequest 
  _Z7sqlplrqP9sqeBsuEduP14SQLP_LOCK_INFO 
  _Z13sqluLockPoolsP8sqeAgentP10sqluCTablej 
  _Z23sqluRegisterLoadRestart 
  _Z29sqluAcquirePartitionResources 
  _Z24sqlu_register_table_load 
 
3) Second index recreate 
 Holding the table space lock in IX mode. 
 Waiting for the latch type identified by 
SQLO_LT_SQLD_TCB_LOTCH__tcbIndexValidityLotch

**************************************************************** 
* USERS AFFECTED:                                              * 
* All users                                                    * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to the latest fix pack.                              * 
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To break the dead latch the LOAD application must be 
interrupted.  This can be done with the FORCE APPLICATION 
command.

DB2 Cancun Release 10.5.0.4 (also known as Fix Pack 4) for Linux, UNIX, and Windows
 DB2 Version 10.5 Fix Pack 9 for Linux, UNIX, and Windows
 

Problem is first fixed in DB2 UDB version 10.5 fix pack 4.

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

22.04.2014
08.09.2014
08.09.2014