DB2 FOR LUW / DB2FORLUW / 970 - DB2

Systems with Health Monitor enabled (HEALTH_MON = ON) may 
experience delays in transaction processing every 2 hours.  This 
is due to health monitor's "backup evaluation" process, which 
needs to query the history file. 
 
The history file processing is inefficient, resulting in holding 
a lock on the history file for a long time if the file is large. 
 If the log writer needs to write to a new log file during this 
period, it will wait for the backup evaluation to complete, as 
this event must be added into the history file, and the log 
writer must acquire the history file lock to do so.  Commit and 
rollback activity, and possibly other database operations, will 
be blocked until the log writer can add the history file entry 
and continue normal processing. 
 
The two-hour interval between delays is a near-certain match for 
this problem.  In addition, a call stack of the db2 log writer 
process (db2loggw) will be similar to the following: 
 
sqloNLCKLock 
sqluhLock 
sqluhAllocateHandleVerifyHistoryFiles 
sqluhOpen 
sqluhBeginBatch 
sqluhInsertSingle 
sqlpAddNewLogToHistFile 
sqlpgOpenNextExt

**************************************************************** 
* USERS AFFECTED:                                              * 
* DB2 Systems with Health Monitor enabled (HEALTH_MON=YES in   * 
* the database manager configuration)                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Suggest using one of the workarounds documented under "Local * 
* Fix"                                                         * 
****************************************************************

Various workarounds exist: 
1. Disable Health Monitor altogether: 
      db2 update dbm cfg using health_mon off ( dynamic if 
issued over an instance attachment ) 
2  Disable the "backup required" health indicator: 
      db2 update alert configuration for database on <database> 
using db.db_backup_req set thresholdschecked no 
3. Prune history log

DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

Problem first fixed in DB2 Version 9.7 Fix Pack 5

see Local Fix

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

10.03.2011
11.05.2012
11.05.2012

9.7.FP5