DB2 FOR LUW / DB2FORLUW / 970 - DB2

DB2 might hang with the following symptomps: 
 
1. There is a lot of latch contention on the following latch 
SQLO_LT_sqeDBMgr__dbMgrLatch. 
2. STMM shows a stack similar to the following: 
 
0x090000001520BD88 sqloWaitEDUWaitPost + 0x218 
0x0900000016D68120 
sqlbRemInvalidPagesFromBufferPool__FP15SQLB_BufferPoolUiN32P12SQ 
LB_GLOBALS + 0x334 
0x0900000016D64DA0 
sqlbDecreaseBufferpoolSize__FP15SQLB_BufferPoolP21SQLB_BP_UC_ALT 
ER_INFOP12SQLB_GLOBALS + 0x554 
0x0900000016D63FE4 
sqlbResizeBufferPool__FP15SQLB_BufferPoolP21SQLB_BP_UC_ALTER_INF 
OP12SQLB_GLOBALS + 0x1E8 
0x09000000165EBBA4 sqlbAlterAutomaticBufferPool__FUiiP8sqeAgent 
+ 0x654 
0x0900000015F3B058 
sqlrlStmmAlterBufferPool__FP8sqeAgentPciT3P14db2UCinterfaceP5sql 
ca + 0x414 
0x0900000015F88784 stmmAlterBufferPool__FP8sqeAgentPciT3 + 0x1F4 
0x0900000015F85924 
stmmResizeRecord__FP21stmmCostBenefitRecordP16sqeLocalDatabase + 
0xEB4 
0x0900000015F838B8 
stmmDecreaseEntriesAndRemoveFromList__FP16sqeLocalDatabasePP21st 
mmCostBenefitRecordPUi + 0xBE0 
0x0900000015F820F0 
stmmResizeEntriesAndRemoveFromList__FPP21stmmCostBenefitRecordP1 
6sqeLocalDatabase + 0xCC 
0x0900000015F81E94 
stmmTuneMemory__FPP21stmmCostBenefitRecordP16sqeLocalDatabase + 
0x11C 
0x0900000015566824 stmmMemoryTunerMain + 0x488 
0x09000000153AA25C sqleIndCoordProcessRequest__FP8sqeAgent + 
0x198 
0x09000000150F1B94 RunEDU__8sqeAgentFv + 0x16C 
0x09000000150EE418 EDUDriver__9sqzEDUObjFv + 0xF4 
0x09000000150E51CC sqloEDUEntry + 0x264 
 
There are not entries in the STMM logs showing this activity. 
 
3. The last agent trying to deactivate the database is on the 
following stack: 
 
0x090000001520BD88 sqloWaitEDUWaitPost + 0x218 
0x09000000150D75C4 sqloWaitEDUWaitPost@glue113 + 0x78 
0x09000000150D6FBC 
TermDbConnect__16sqeLocalDatabaseFP8sqeAgentP5sqlcai + 0x620 
0x09000000150D282C 
AppStopUsing__14sqeApplicationFP8sqeAgentUcP5sqlca + 0xD88 
0x09000000153E40F4 sqlesrspWrp__FP14db2UCinterface + 0xA8 
0x09000000153E4368 sqleUCagentConnectReset + 0xF8 
0x0900000015429340 
@63@sqljsCleanup__FP8sqeAgentP14db2UCconHandle + 0x910 
0x090000001542A2F0 
@63@sqljsDrdaAsInnerDriver__FP18SQLCC_INITSTRUCT_Tb + 0x330 
0x0900000015429D1C sqljsDrdaAsDriver__FP18SQLCC_INITSTRUCT_T + 
0x100 
0x09000000150F1D1C RunEDU__8sqeAgentFv + 0x2F4 
0x09000000150EE418 EDUDriver__9sqzEDUObjFv + 0xF4 
0x09000000150E51CC sqloEDUEntry + 0x264 
 
4. At some point in time there are entries in the db2diag.log 
like which have the message "Sort Error. Failed sanity check 
before unfixing page, fixount is 0, aborting sort" as key: 
 
 
FUNCTION: DB2 UDB, sort/list services, 
sqlsSanityCheckPageAlreadyUnfixed, probe:4099 
MESSAGE : ZRC=0x82130001=-2112684031=SQLS_NONSEVERE_PE 
          "Sort List Services programming error." 
          DIA8532C An internal processing error has occurred. 
DATA #1 : String, 81 bytes 
Sort Error. Failed sanity check before unfixing page, fixount is 
0, aborting sort 
DATA #2 : Fix control block, PD_TYPE_SQLB_FIX_CB, 168 bytes 
  accessMethod:  SQLB_POOL_RELATIVE 
  fixMode:                        2   SQLBOLD/SQLBOLDS 
  buffptr:       0x0000000000000000 
  bpdPtr:        0x0770000024973170 
  dmDebugHdl:                     0 
  objectPageNum:               2280 
  empDiskPageNum:         4294967295 
  unfixFlags:                     6   SQLB_UFIX_PURGE_MODE | 
SQLB_UFIX_DEFERRED_MODE 
  dirtyState:    SQLBCLEAN 
  fixInfoFlags: 
  regEDUid:      0 
  Pagekey: {pool:1;obj:2;type:128} PPNum:2280 
 
And there is a matching trap file with a stack like: 
 
pthread_kill + 0x88 
 
 sqloDumpEDU + 0x34 
 
 sqldDumpContext__FP9sqeBsuEduiN42PCcPvT2 + 0xC4 
 
 sqldDumpContext__FP9sqeBsuEduiN42PCcPvT2@glue5AE + 0x98 
 
 sqlrr_dump_ffdc__FP8sqlrr_cbiT2 + 0x388 
 
 sqlzeDumpFFDC__FP8sqeAgentUiP5sqlcai + 0x30 
 
 sqlzeDumpFFDC__FP8sqeAgentUiP5sqlcai@glue534 + 0x80 
 
 sqlzeMapZrc__FP8sqeAgentUiUlT2P5sqlcaiPC12sqlzeContextb + 0x1F8 
 
 sqlrrMapZrc__FP8sqlrr_cbUiUli@glue3C3 + 0x80 
 
 sqlriclo__FP8sqlrr_cbP9sqlri_taoi + 0xA8 
 
 sqlriclo__FP8sqlrr_cbP9sqlri_taoi@glueBA6 + 0x78 
 
 sqlricjp__FP8sqlrr_cbP12sqlri_opparmilT4 + 0x30 
 
 sqlricls_simple__FP8sqlrr_cbil + 0x170 
 
 sqlrr_process_close_request__FP8sqlrr_cbiN32 + 0x18C 
 
 sqlrr_close__FP14db2UCinterfaceP15db2UCCursorInfo + 0x304 
 
 sqljs_ddm_clsqry__FP14db2UCinterfaceP13sqljDDMObject + 0x760 
 
 
sqljsParseRdbAccessed__FP13sqljsDrdaAsCbP13sqljDDMObjectP14db2UC 
interface + 0x180 
 
.sqljsParse.fdpr.clone.0__FP13sqljsDrdaAsCbP14db2UCinterfaceP8sq 
eAgentb + 0x6DC 
 @63@sqljsSqlam__FP14db2UCinterfaceP8sqeAgentb + 0x2D4 
 
 @63@sqljsDriveRequests__FP8sqeAgentP14db2UCconHandle + 0xB4 
 
 @63@sqljsDrdaAsInnerDriver__FP18SQLCC_INITSTRUCT_Tb + 0x2D0 
 
 
This might show also with entries similar to : 
 
 
FUNCTION: DB2 UDB, sort/list services, 
sqlsSanityCheckPageAlreadyUnfixed, probe:4099 
MESSAGE : ZRC=0x82130001=-2112684031=SQLS_NONSEVERE_PE 
          "Sort List Services programming error." 
          DIA8532C An internal processing error has occurred. 
DATA #1 : String, 81 bytes 
Sort Error. Failed sanity check before unfixing page, fixount is 
0, 
aborting sort 
DATA #2 : Fix control block, PD_TYPE_SQLB_FIX_CB, 168 bytes 
  accessMethod:  SQLB_POOL_RELATIVE 
  fixMode:                        2   SQLBOLD/SQLBOLDS 
  buffptr:       0x0000000000000000 
  bpdPtr:        0x07700000ca4af6a0 
  dmDebugHdl:                     0 
  objectPageNum:                  4 
  empDiskPageNum:         4294967295 
  unfixFlags:                     2   SQLB_UFIX_PURGE_MODE 
  dirtyState:    SQLBCLEAN 
  fixInfoFlags:Page 4 of 9 
  regEDUid:      0 
  Pagekey: {pool:1;obj:2;type:128} PPNum:4 
 
.... 
CALLSTCK: (Static functions may not be resolved correctly, as 
they are 
resolved to the nearest symbol) 
  [0] 0x0900000012A79A84 pdLog + 0xF4 
  [1] 0x090000001410A168 pdLog@glue421 + 0x12C 
  [2] 0x09000000133A8E6C 
sqlsmergerec__FP8sqeAgentP10SQLS_SLDESP10SQLS_MBUFSUl + 0x260 
  [3] 0x09000000128E0BA0 
sqlsfetc__FP8sqeAgentP8SQLD_CCBiP10SQLD_DPREDPP10SQLD_VALUEP8SQL 
Z_RIDPc + 0x438 
  [4] 0x0900000012A5F288 
sqlriPrefetchRIDs__FP8sqlrr_cbP8sqlri_lfl + 0x260 
  [5] 0x09000000128E1BD0 sqlriListFetch__FP8sqlrr_cb + 0x4C 
  [6] 0x090000001293B16C sqlriNljnPiped__FP8sqlrr_cb + 0x26C 
  [7] 0x090000001293C624 
sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm + 0x30 
  [8] 0x0900000012B6F024 
sqlrr_process_fetch_request__FP14db2UCinterface + 0x1C0 
  [9] 0x09000000129A68D0 
sqlrr_fetch__FP14db2UCinterfaceP15db2UCCursorInfo + 0x38C 
 
 
The hung situation is due to the sort problem documented in 
point 4 above. 
STMM will hang on the page after the sort failure, making it 
impossible to deactivate the database or allowing 
new connections.

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to Db2 Version 9.7 and Fix Pack 9.                   * 
****************************************************************

Make sure that you explicitly activate the database with "db2 
activate database..." which will avoid hangs on disconnections 
of the last agent. Note that if you hit this issue, even after 
activating the database explicitly, STMM will still be stuck and 
you might need to restart the database for it to continue 
working.

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 was first fixed in DB2 Version 9.7 and Fix Pack 9.

not known / see Local fix

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

07.06.2013
17.12.2013
17.12.2013

9.0.,
9.7.