DB2 FOR LUW / DB2FORLUW / 970 - DB2

Rollback of a deferred buffer pool alter causes an instance 
abend in sqlbUnChainUCAlter. This problem has been present for 
several releases, but due to the unusual sequence of steps 
needed to recreate the problem the issue has not been reported 
by an end customer yet (only discovered internally). For this 
reason the problem should be of low severity for most customers. 
 
Sample scenario: 
 
db2 "connect to sample" 
db2 "create bufferpool mybp size 1000 automatic" 
db2 "create tablespace ts2 bufferpool mybp" 
db2 "alter tablespace ts2 bufferpool ibmdefaultbp" 
db2 "drop bufferpool mybp" (should return SQL20225W) 
db2 +c "create bufferpool mybp size 1000 automatic" (should 
return SQL20169W) 
db2 +c "alter bufferpool mybp deferred size 740" 
db2 +c "rollback" 
 
SQL1224N  The database manager is not able to accept new 
requests, has 
terminated all requests in progress, or has terminated the 
specified request 
because of an error or a forced interrupt.  SQLSTATE=55032 
 
The DB2 diagnostic log will contain SQLB_BUFF_NOT_STARTED 
warnings just prior to the abend: 
 
2011-10-26-19.17.12.013863-240 E39174190A571      LEVEL: Warning 
PID     : 26607784             TID  : 21484       PROC : db2sysc 
1 
INSTANCE: db2inst1             NODE : 001         DB   : SAMPLE 
APPHDL  : 1-7868               APPID: *N1.db2inst1.111026231630 
AUTHID  : DB2INST1 
EDUID   : 21484                EDUNAME: db2agntp (SAMPLE) 1 
FUNCTION: DB2 UDB, buffer pool services, sqlbAlterBufferPool, 
probe:80 
MESSAGE : ZRC=0x8002014A=-2147352246=SQLB_BUFF_NOT_STARTED 
          "Bufferpool not started" 
DATA #1 : String, 43 bytes 
(Informational) Warning, alter was deferred 
 
2011-10-26-19.17.14.147063-240 I39174762A492      LEVEL: Warning 
PID     : 26607784             TID  : 39885       PROC : db2sysc 
1 
INSTANCE: db2inst1             NODE : 001         DB   : SAMPLE 
APPHDL  : 1-7868               APPID: *N1.db2inst1.111026231630 
AUTHID  : DB2INST1 
EDUID   : 39885                EDUNAME: db2agent (SAMPLE) 1 
FUNCTION: DB2 UDB, RAS/PD component, 
pdEDUIsInDB2KernelOperation, probe:600 
DATA #1 : String, 22 bytes 
 sqlbUnChainUCAlter__F 
DATA #2 : String, 4 bytes 
sqlb 
 
The trap file will contain sqlbUnChainUCAlter on top of the call 
stack: 
 
EDU name     : db2agent (SAMPLE) 1 
Signal #11 
 
GPR[03]: 0000000000000000 
GPR[29]: 0000000000000000 
 
>>>> 0x0900000007345540 : F87D0000 std r3,0(r29) 
 
Signal #11 (SIGSEGV): si_addr is 0x0000000000000000, si_code is 
0x00000033 
 
sqlbUnChainUCAlter 
undoAlterBufferPool 
sqlbUndo 
sqldmund 
sqlptudo 
sqlptud1 
sqlpxrbk 
sqlrkrbk 
sqlrkrbk 
sqlrrbck_dps 
sqlrrbck 
sqlrr_rollback

**************************************************************** 
* USERS AFFECTED:                                              * 
* see APAR description                                         * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* see APAR description                                         * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 UDB 9.7 Fix Pack 6                            * 
****************************************************************

Avoid rolling back a deferred buffer pool alter. If possible, 
commit the ALTER BUFFERPOOL statement, then back out the alter 
as desired by issuing another ALTER BUFFERPOOL statement, 
reverting to the desired buffer pool values. The second ALTER 
BUFFERPOOL statement will be carried out by another transaction, 
and the abend will not happen.

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
 

The problem was first fixed in DB2 UDB 9.7 Fix Pack 6

keiner bekannt / siehe Local-Fix

Vorgänger  : APAR is sysrouted TO one or more of the following: IC84151 
Nachfolger : 

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

17.11.2011
05.06.2012
05.06.2012

9.7.FP6