|
Problem IC88663
|
Status: Closed |
HIGH NUMBER OF PREFETCHER REQUESTS CAUSING HIGH SYS% AND PERFORMANCE DEGRADATION |
| product: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problem description: |
During heavy workload, high number of prefetcher requests can
cause latch contention which in turn will cause SYS CPU increase
and performance impact on running transactions.
The latch contention during this time is on prefetcher free list
latch: SQLO_LT_SQLB_pfCB__freeListLatch
From db2pd -latches collected during the issue, we can see high
number of waiters for this latch:
0x070000212508F160 282449 359566 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 593521 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 66545 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 240148 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 190171 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 218614 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 112921 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 115485 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 185929 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 208715 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 234577 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 238165 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 243544 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
0x070000212508F160 282449 249185 sqlbpfgen.C
1441 SQLO_LT_SQLB_pfCB__freeListLatch 1
The stack dumps may look as follows:
sqloXlatchConflict + 0x29C
sqloXlatchConflict@glue1AC + 0x78
sqlbPFAddFreeRequest__FPP14SQLB_pfRequestP12SQLB_GLOBALS + 0x24
sqlbPFAddFreeRequest__FPP14SQLB_pfRequestP12SQLB_GLOBALS@glue552
+ 0x74
sqldmPrefetchList__FP8sqeAgentP8SQLD_CCBPP14SQLB_pfRequesti +
0x3E8
sqldmPrefetchList__FP8sqeAgentP8SQLD_CCBPP14SQLB_pfRequesti@glue
EBB + 0x78
sqlriPrefetchRIDs__FP8sqlrr_cbP8sqlri_lfl + 0x33C
sqlriPrefetchRIDs__FP8sqlrr_cbP8sqlri_lfl@glue1505 + 0x74
sqlriListFetch__FP8sqlrr_cb + 0x248
sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm + 0x28
sqlrr_process_execute_request__FP8sqlrr_cbi + 0xC74
sqlrr_execute__FP14db2UCinterfaceP9UCstpInfo + 0x224
executeSection__10pvmPackageFP5sqlcaUib + 0x548
executeQuery__3PVMFUib + 0x1B4
run__3PVMFv + 0x18C
pvm_entry + 0x498
sqloInvokeFnArgs + 0xEC
sqloInvokeFnArgs@glue4C3 + 0x78
sqlriInvokerTrusted__FP10sqlri_ufobP21sqlriRoutineErrorIntf +
0x1C8
sqlriInvokeInvoker__FP10sqlri_ufobb + 0xB9C
or/and
sqloSpinLockReleaseConflict + 0xC0
sqloSpinLockReleaseConflict@glue74 + 0x78
sqlbPFGetFreeRequest__FUiiPP14SQLB_pfRequestP12SQLB_GLOBALS +
0x4
sqlbPFGetFreeRequest__FUiiPP14SQLB_pfRequestP12SQLB_GLOBALS@glue
551 + 0x7C
sqldmPrefetchList__FP8sqeAgentP8SQLD_CCBPP14SQLB_pfRequesti +
0x114
sqldmPrefetchList__FP8sqeAgentP8SQLD_CCBPP14SQLB_pfRequesti@glue
EBB + 0x78
sqlriPrefetchRIDs__FP8sqlrr_cbP8sqlri_lfl + 0x33C
sqlriPrefetchRIDs__FP8sqlrr_cbP8sqlri_lfl@glue1505 + 0x74
sqlriListFetch__FP8sqlrr_cb + 0x248
sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm + 0x28
sqlrr_process_execute_request__FP8sqlrr_cbi + 0xC74
sqlrr_execute__FP14db2UCinterfaceP9UCstpInfo + 0x224
executeSection__10pvmPackageFP5sqlcaUib + 0x548
executeQuery__3PVMFUib + 0x1B4
run__3PVMFv + 0x18C
pvm_entry + 0x498
sqloInvokeFnArgs + 0xEC
sqloInvokeFnArgs@glue4C3 + 0x78
sqlriInvokerTrusted__FP10sqlri_ufobP21sqlriRoutineErrorIntf +
0x1C8
sqlriInvokeInvoker__FP10sqlri_ufobb + 0xB9C |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to the latest fix pack. *
**************************************************************** |
| Local Fix: |
No Local Fix |
| available fix packs: |
DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows
|
| Solution |
Problem was first fixed in DB2 UDB version 10.1 fix pack 2. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.11.2012
20.12.2012
20.12.2012 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 10.1.0.2
|
 |
| 10.5.0.2
|
|
