In rare timing conditions when operating on range partitioned
tables, DB2 may panic and the instance is brought down. This
timing scenario is most likely to occur when using admin table
functions. In the db2diag.log, there will be an error message
stating "SQLO_LATCH_ERROR_EXPECTED_HELD". The complete message
entry should be similar to the following:
2011-03-09-06.18.46.684025-300 E86584573A2413 LEVEL: Severe
(OS)
PID : 7077944 TID : 34965 PROC : db2sysc
0
INSTANCE: svtdbm4 NODE : 000 DB : DASZDB
APPHDL : 0-33072 APPID:
*LOCAL.svtdbm4.110309145201
AUTHID : SVTDBM4
EDUID : 34965 EDUNAME: db2agent (DASZDB) 0
FUNCTION: DB2 UDB, SQO Latch Tracing,
SQLO_SLATCH_CAS64::releaseConflictComple, probe:330
MESSAGE :
ZRC=0x870F011E=-2029059810=SQLO_LATCH_ERROR_EXPECTED_HELD
"expected latch to be held."
CALLED : OS, -, unspecified_system_function
DATA #1 : String, 39 bytes
Attempting to unlock an invalid latch:
DATA #2 : File name, 16 bytes
sqloLatchCAS64.C
DATA #3 : Source file line number, 8 bytes
982
DATA #4 : Codepath, 8 bytes
4
DATA #5 : String, 125 bytes
0x0000000000000000: {
held X: 0
reserved for X: 0
shared holders: 0
firstSharIndex: 0x0
firstExclIndex: 0x0
}
DATA #6 : LatchMode, PD_TYPE_LATCH_MODE, 8 bytes
0x0 (invalid mode)
DATA #7 : String, 406 bytes
{
state = 0x0000000000000000
= {
held X: 0
reserved for X: 0
shared holders: 0
firstSharIndex: 0x0
firstExclIndex: 0x0
}
starve X mode = false
xWaitCount = 0
requestCount = 0
identity = SQLD_CHAIN::fullChainLatchNS (244)
}
DATA #8 : Hexdump, 16 bytes
0x0A000300E1305D00 : 0000 0000 0000 0000 80F4 0000 0000 0000
................
CALLSTCK:
[0] 0x090000000DE8BA88 pdLogSysRC + 0x1D0
[1] 0x090000000A4116E4
dumpDiagInfoAndPanic__17SQLO_SLATCH_CAS64CFCPCcCUiCUlT3ClT3CiT1T
3T7
+ 0x2BC
[2] 0x0900000009DFA7E8
dumpDiagInfoAndPanic__17SQLO_SLATCH_CAS64CFCPCcCUiCUlT3ClT3CiT1T
3T7@glue32D
+ 0x9C
[3] 0x090000000A131CEC
releaseConflictComplex__17SQLO_SLATCH_CAS64Fv + 0x220
[4] 0x090000000DCB50F4
releaseConflictComplex__17SQLO_SLATCH_CAS64Fv@glue32E + 0x78 |
****************************************************************
* USERS AFFECTED: *
* All users with range partitioned tables *
****************************************************************
* PROBLEM DESCRIPTION: *
* In limited scenarios, a rare timing hole could cause an *
* internal latch to be unlatched twice, triggering the *
* SQLO_LATCH_ERROR_EXPECTED_HELD error message in the *
* db2diag.log. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.5 Fix Pack 8. *
**************************************************************** |
