DB2 FOR LUW / DB2FORLUW / 980 - DB2

PROBLEM DESCRIPTION: 
==================== 
When using Scalar Aggregation functions with Connection 
Concentrator enabled, memory allocated for the scalar 
aggregation execution may become invalid when the connection is 
serviced by different agents, causing DB2 to trap/abend.  An 
additional requirement is that "with hold cursors" are being 
used, but this is common. 
 
Connection Concentrator is enabled when the database manager 
configuration parameter MAX_CONNECTIONS exceeds MAX_COORDAGENTS. 
This criteria applies when these parameters are set to 
AUTOMATIC, in which case the criteria applies to the underlying 
values. 
For example, this configuration shows Connection Concentrator 
enabled: 
 Max number of coordinating agents     (MAX_COORDAGENTS) = 
AUTOMATIC(200) 
 Max number of client connections      (MAX_CONNECTIONS) = 
AUTOMATIC(1000) 
 
Example diagnostic trap files will include the keyword/function 
sqlriScalagClose: 
 
Example 1: 
<StackTrace> 
... 
sqloEDUCodeTrapHandler + 0x0107 
address: 0x00002AAAAABD4C00 
sqldmcloP8sqeAgentPP8SQLD_CCBi + 0x002a 
sqlriScalagCloseDropTempP8sqlrr_cbP16sqlri_buffer_mgr + 0x007f 
sqlri_buffer_closeP8sqlrr_cbP15sqlri_scalagobj + 0x021d 
sqlriScalagCloseP8sqlrr_cbP15sqlri_scalagobj + 0x003c 
 
Example 2: 
<StackTrace> 
... 
sqloCrashOnCriticalMemoryValidationFailure + 0x1C 
diagnoseMemoryCorruptionAndCrash__13SQLO_MEM_POOLFUlCPCc + 0x260 
sqloDiagnoseFreeBlockFailure__FP8SMemFBlk + 0x748 
sqloDiagnoseFreeBlockFailure__FP8SMemFBlk@glue69E + 0x74 
sqlofmblkEx + 0x48 
sqlri_buffer_close__FP8sqlrr_cbP15sqlri_scalagobj + 0xB0 
sqlriScalagClose__FP8sqlrr_cbP15sqlri_scalagobj + 0x2C 
sqlriScalagClose__FP8sqlrr_cbP15sqlri_scalagobj@glue10D1 + 0x70 
sqlricjpInfrequent__FP8sqlrr_cbPP12sqlri_opparml + 0x4 
sqlricjp__FP8sqlrr_cbP12sqlri_opparmilT4 - 0x170 
sqlricls_simple__FP8sqlrr_cbil + 0xCC

**************************************************************** 
* USERS AFFECTED:                                              * 
* Systems configured to use Connection Concentrator            * 
* (MAX_CONNECTIONS > MAX_COORDAGENTS)                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.8 Fix Pack 4 or higher or disable   * 
* Connection Concentrator (set MAX_COORDAGENTS equal to        * 
* MAX_CONNECTIONS)                                             * 
****************************************************************

Disable Connection Concentrator: 
db2 update dbm cfg using MAX_CONNECTIONS -1 automatic 
db2stop;db2start 
 
This results in the following standard configuration: 
 Max number of coordinating agents     (MAX_COORDAGENTS) = 
AUTOMATIC(200) 
 Max number of client connections      (MAX_CONNECTIONS) = 
AUTOMATIC(MAX_COORDAGENTS)

DB2 Version 9.8 Fix Pack 4 for AIX and Linux
 DB2 Version 9.8 Fix Pack 5 for AIX and Linux
 

Problem first fixed in DB2 Version 9.8 Fix Pack 4

not known / see Local fix

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

24.03.2010
12.08.2011
12.08.2011

9.8.FP4