Regarding DB2 Load operation, one option of load "MODIFIED BY"
with "METHOD L", specifies the start and end column numbers from
which to load data. A column number is a byte offset from the
beginning of a row of data. It is numbered starting from 1. This
method can only be used with ASC files, and is the only valid
method for that file type.
In this load command's METHOD L (beginloc endloc), the offset of
endloc must be greater or equal to beginloc otherwise the load
operation will be failing gracefully with thus certain invalid
input.
But in a DPF environment, if there is a invalid input of METHOD
L (The endloc is less than beginloc) to the column that is part
of the table's distribution key, the load operation will cause
the instance crash. Because the load db2lpart EDU (load
partitioning SA) is handed a string with "negative length", and
DB2 are missing code that check for this matter.
As db2diag.log reported:
2011-01-12-19.32.02.412374-300 I182007E1756 LEVEL: Severe
PID : 7133 TID : 183274301792 PROC :
db2sysc 1
INSTANCE: myname NODE : 001 DB :
V95MPP2
APPHDL : 0-79 APPID: *N0.myname.110113003126
AUTHID : MYNAME
EDUID : 117 EDUNAME: db2lpart 1
FUNCTION: DB2 UDB, SQO Memory Management,
sqloDiagnoseFreeBlockFailure, probe:10
MESSAGE : Possible memory corruption detected.
DATA #1 : ZRC, PD_TYPE_ZRC, 4 bytes
0x820F0002
DATA #2 : Corrupt block address, PD_TYPE_CORRUPT_BLK_PTR, 8
bytes
0x0000002ac4d94000
DATA #3 : Block header, PD_TYPE_BLK_HEADER, 24 bytes
0x0000002AC4D93FE8 : 0000 0000 0000 0000 0000 0000 0000 0000
................
0x0000002AC4D93FF8 : 0000 0000 0000 0000
........
DATA #4 : Data header, PD_TYPE_BLK_DATA_HEAD, 48 bytes
0x0000002AC4D94000 : 0000 0000 0000 0000 A040 D9C4 2A00 0000
.........@..*...
0x0000002AC4D94010 : 0000 0000 0000 0000 0000 0000 0000 0000
................
0x0000002AC4D94020 : 0000 0000 0000 0000 8B4D AC02 0000 B0FA
.........M......
CALLSTCK:
[0] 0x0000002A9684EA93 pdLog + 0xD7
[1] 0x0000002A97ED8C0D
/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1 +
0x2756C0D
[2] 0x0000002A98A7C4A5 sqlofmblkEx + 0x8B9
[3] 0x0000002A968387EC _Z9sqlofmblkPv + 0x6
[4] 0x0000002A96DD8DB1 _ZN13sqluCLinkList8bCleanUpEv + 0x1F
[5] 0x0000002A985715B4 _ZN17sqluCSerializable11iDeallocateEv +
0x140
[6] 0x0000002A987C273A
_ZN27sqlusCPartRequestDescriptor11iDeallocateEv + 0x6
[7] 0x0000002A987C65F1 _ZN18sqlusCPartSubAgent8iCleanUpEv +
0x3C1
[8] 0x0000002A987DAD4A _Z19sqlusSubAgentRouterP8sqeAgenti +
0x28E
[9] 0x0000002A973310E0 _Z20sqleSubRequestRouterP8sqeAgentPjS1_
+ 0x324
2011-01-12-19.32.02.421800-300 E183764E953 LEVEL:
Critical
PID : 7133 TID : 183274301792 PROC :
db2sysc 1
INSTANCE: myname NODE : 001 DB :
V95MPP2
APPHDL : 0-79 APPID: *N0.myname.110113003126
AUTHID : MYNAME
EDUID : 117 EDUNAME: db2lpart 1
FUNCTION: DB2 UDB, SQO Memory Management,
sqloDiagnoseFreeBlockFailure, probe:10
MESSAGE : ADM14001C An unexpected and critical error has
occurred: "Panic".
The instance may have been shutdown as a result.
"Automatic" FODC
(First Occurrence Data Capture) has been invoked and
diagnostic
information has been recorded in directory
"/home/hotel20/myname/sqllib/db2dump/FODC_Panic_2011-01-12-19.32
.02.4
21661/". Please look in this directory for detailed
evidence about
what happened and contact IBM support if necessary to
diagnose the
problem.
2011-01-12-19.32.02.429430-300 E184718E1269 LEVEL: Severe
PID : 7133 TID : 183274301792 PROC :
db2sysc 1
INSTANCE: myname NODE : 001 DB :
V95MPP2
APPHDL : 0-79 APPID: *N0.myname.110113003126
AUTHID : MYNAME
EDUID : 117 EDUNAME: db2lpart 1
FUNCTION: DB2 UDB, SQO Memory Management,
sqloDiagnoseFreeBlockFailure, probe:999
MESSAGE : Memory validation failure, diagnostic file dumped.
DATA #1 : String, 21 bytes
Invalid block header.
DATA #2 : File name, 37 bytes
7133.183274301792.mem_diagnostics.txt
CALLSTCK:
[0] 0x0000002A9684EA93 pdLog + 0xD7
[1] 0x0000002A97EDE3EA
_ZN13SQLO_MEM_POOL32diagnoseMemoryCorruptionAndCrashEmPKc +
0x200
[2] 0x0000002A97ED8E62
/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1 +
0x2756E62
[3] 0x0000002A98A7C4A5 sqlofmblkEx + 0x8B9
[4] 0x0000002A968387EC _Z9sqlofmblkPv + 0x6
[5] 0x0000002A96DD8DB1 _ZN13sqluCLinkList8bCleanUpEv + 0x1F
[6] 0x0000002A985715B4 _ZN17sqluCSerializable11iDeallocateEv +
0x140
[7] 0x0000002A987C273A
_ZN27sqlusCPartRequestDescriptor11iDeallocateEv + 0x6
[8] 0x0000002A987C65F1 _ZN18sqlusCPartSubAgent8iCleanUpEv +
0x3C1
[9] 0x0000002A987DAD4A _Z19sqlusSubAgentRouterP8sqeAgenti +
0x28E
2011-01-12-19.32.02.469188-300 I185988E553 LEVEL: Error
PID : 7133 TID : 183274301792 PROC :
db2sysc 1
INSTANCE: myname NODE : 001 DB :
V95MPP2
APPHDL : 0-79 APPID: *N0.myname.110113003126
AUTHID : MYNAME
EDUID : 117 EDUNAME: db2lpart 1
FUNCTION: DB2 UDB, base sys utilities, sqleagnt_sigsegvh,
probe:1
MESSAGE : Error in agent servicing application with coor_node:
DATA #1 : Hexdump, 2 bytes
0x0000002AABC0FA32 : 0000
..
...
and the associated stack trace reported:
<StackTrace>
-----FUNC-ADDR---- ------FUNCTION + OFFSET------
0x0000002A9BB4C0E7 ossDumpStackTraceEx + 0x01f7
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2osse.so.
1)
0x0000002A9BB47BBA _ZN11OSSTrapFile6dumpExEmiP7siginfoPvm +
0x00b4
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2osse.so.
1)
0x0000002A9BB47C81 _ZN11OSSTrapFile4dumpEmiP7siginfoPv + 0x0009
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2osse.so.
1)
0x0000002A97EA3C19 sqlo_trce + 0x0425
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A97EE5D24 sqloEDUCodeTrapHandler + 0x0138
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A95679260 address: 0x0000002A95679260 ; dladdress:
0x0000002A9566D000 ; offset in lib: 0x000000000000C260 ;
(/lib64/tls/libpthread.so.0)
0x0000002A97ED8A66 sqloCrashOnCriticalMemoryValidationFailure +
0x001a
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A97EDE3EF
_ZN13SQLO_MEM_POOL32diagnoseMemoryCorruptionAndCrashEmPKc +
0x0205
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A97ED8E62 address: 0x0000002A97ED8E62 ; dladdress:
0x0000002A95782000 ; offset in lib: 0x0000000002756E62 ;
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A98A7C4A5 sqlofmblkEx + 0x08b9
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A968387EC _Z9sqlofmblkPv + 0x0006
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A96DD8DB1 _ZN13sqluCLinkList8bCleanUpEv + 0x001f
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A985715B4 _ZN17sqluCSerializable11iDeallocateEv +
0x0140
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A987C273A
_ZN27sqlusCPartRequestDescriptor11iDeallocateEv + 0x0006
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A987C65F1 _ZN18sqlusCPartSubAgent8iCleanUpEv + 0x03c1
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A987DAD4A _Z19sqlusSubAgentRouterP8sqeAgenti + 0x028e
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A973310E0 _Z20sqleSubRequestRouterP8sqeAgentPjS1_ +
0x0324
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A973307B5 _Z21sqleProcessSubRequestP8sqeAgent + 0x005f
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A96941765 _ZN8sqeAgent6RunEDUEv + 0x04b7
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A96E4CE3D _ZN9sqzEDUObj9EDUDriverEv + 0x006d
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A96E4CDCD _Z10sqlzRunEDUPcj + 0x0009
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A96C32E06 sqloEDUEntry + 0x02ea
(/view/db2_v95fp5_linuxamd64_s091123/vbs/INST/lib/libdb2e.so.1)
0x0000002A95673919 address: 0x0000002A95673919 ; dladdress:
0x0000002A9566D000 ; offset in lib: 0x0000000000006919 ;
(/lib64/tls/libpthread.so.0)
0x0000002A9C497573 __clone + 0x0043
(/lib64/tls/libc.so.6)
</StackTrace>
If striptblanks or striptnulls option is used in the load
command, then there may not be memory validation failure error
entries in db2diag.log, but it will still show the db2lpart EDU
crashing, and the stack trace may look like
<StackTrace>
-------Frame------ ------Function + Offset------
0x090000000EB1FE10
iPartitionData__18sqlusCPartSubAgentFP16sqluIMediaListIOT1 +
0x3E4
0x090000000E8BFD28 iRun__18sqlusCPartSubAgentFv + 0x96C
0x090000000D7A8558 sqlusSubAgentRouter__FP8sqeAgenti + 0x8CC
0x090000000D79C478 sqleSubRequestRouter__FP8sqeAgentPUiT2 +
0x1008
0x090000000D79AE58 sqleProcessSubRequest__FP8sqeAgent + 0x124
0x090000000EA46D04 RunEDU__8sqeAgentFv + 0x300
0x090000000DF79FCC EDUDriver__9sqzEDUObjFv + 0x78
0x090000000DD14ED0 sqlzRunEDU__FPcUi + 0xC
0x090000000DD14F18 sqloEDUEntry + 0x4
</StackTrace> |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* Regarding DB2 Load operation, one option of load "MODIFIED *
* BY"with "METHOD L", specifies the start and end column *
* numbers from which to load data. A column number is a byte *
* offset from the beginning of a row of data. It is numbered *
* starting from 1. This method can only be used with ASC *
* files, and is the only valid method for that file type. *
* *
* In this load command's METHOD L (beginloc endloc), the *
* offset of endloc must be greater or equal to beginloc *
* otherwise the load operation will be failing gracefully with *
* thus certain invalid input. *
* *
* But in a DPF environment, if there is a invalid input of *
* METHOD L (The endloc is less than beginloc) to the column *
* that is part of the table's distribution key, the load *
* operation will cause the instance crash. Because the load *
* db2lpart EDU (load partitioning SA) is handed a string with *
* "negative length", and DB2 are missing code that check for *
* this matter. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.5 Fix Pack 8 *
* *
* OR *
* *
* Correcting usage of the db2 load option METHOD L *
* (beginloc endloc), the offset of endloc must be greater or *
* equal to beginloc. *
**************************************************************** |
