|
Problem IT27943
|
Status: Closed |
Deadlatch between an online backup, prefetchers and an agent doing a write to the same table space
|
| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
A deadlatch might happen when an online backup is holding the
latch SQLO_LT_SQLB_POOL_CB__readLotch in S mode and waiting on
free prefetcher requests in the following stack:
-----FUNC-ADDR---- ------FUNCTION + OFFSET------
0x00007FCD0390CCA6
_Z25ossDumpStackTraceInternalmR11OSSTrapFileiP7siginfoPvmm +
0x0356
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0390C8EB ossDumpStackTraceV98 + 0x002b
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD03908AD7 _ZN11OSSTrapFile6dumpExEmiP7siginfoPvm +
0x00d7
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0B170187 sqlo_trce + 0x03c7
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B2DBC0B sqloDumpDiagInfoHandler + 0x020b
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD12E71680 address: 0x00007FCD12E71680 ; dladdress:
0x00007FCD12E62000 ; offset in lib: 0x000000000000F680 ;
(/lib64/libpthread.so.0)
0x00007FCD029172A3 msgrcv + 0x0033
(/lib64/libc.so.6)
0x00007FCD0B27C259 sqloCSemP + 0x0279
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05DB6D14
_Z26sqlbPFFindAndLatchFreelistiPP15SQLB_pfFreelistP12SQLB_GLOBAL
S + 0x04b4
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05DBA0F8
_Z29sqlbPFGetMultipleFreeRequestsjiPP14SQLB_pfRequestPmP12SQLB_G
LOBALS14SQLB_pfReqTypeP16SQLB_OBJECT_DESCt + 0x0068
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05DB87DA
_Z25sqlbpfParallelDirectReadVP14SQLB_pfParIoCbP17SQLB_DIRECT_IO_
CB + 0x18aa
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05BE2FDD
_Z19sqlbDirectReadBlockP19SQLB_DIRECT_READ_CBP14SQLB_pfParIoCbjP
jS3_ + 0x05dd
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD09C5B295 _Z12sqlubReadDMSP14SQLU_BUFMAN_CB + 0x0485
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD09C59C14 _Z18sqlubBMProcessDataP14SQLU_BUFMAN_CB +
0x0304
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD09C5915F _Z8sqlubbufP8sqeAgent + 0x051f
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD09476320 _Z26sqleSubCoordProcessRequestP8sqeAgent +
0x0150
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD094931AE _ZN8sqeAgent6RunEDUEv + 0x05ae
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0CDB321E _ZN9sqzEDUObj9EDUDriverEv + 0x01be
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B2D96BA sqloEDUEntry + 0x057a
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD12E69DD5 address: 0x00007FCD12E69DD5 ; dladdress:
0x00007FCD12E62000 ; offset in lib: 0x0000000000007DD5 ;
(/lib64/libpthread.so.0)
0x00007FCD02915B3D clone + 0x006d
(/lib64/libc.so.6)
An agent trying to make some change to the same table space is
waiting behind the online backup on the latch
SQLO_LT_SQLB_POOL_CB__readLotch in X mode, a sample stack is as
follow. Note it is not always the same stack because it depends
on what writing operation this agent is doing to the table
space.
-----FUNC-ADDR---- ------FUNCTION + OFFSET------
0x00007FCD0390CCA6
_Z25ossDumpStackTraceInternalmR11OSSTrapFileiP7siginfoPvmm +
0x0356
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0390C8EB ossDumpStackTraceV98 + 0x002b
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD03908AD7 _ZN11OSSTrapFile6dumpExEmiP7siginfoPvm +
0x00d7
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0B170187 sqlo_trce + 0x03c7
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B2DBC0B sqloDumpDiagInfoHandler + 0x020b
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD12E71680 address: 0x00007FCD12E71680 ; dladdress:
0x00007FCD12E62000 ; offset in lib: 0x000000000000F680 ;
(/lib64/libpthread.so.0)
0x00007FCD02917337 semop + 0x0007
(/lib64/libc.so.6)
0x00007FCD0B16E3A2 _ZN17SQLO_SLATCH_CAS6418getConflictComplexEm
+ 0x07e2
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B16DBBC _ZN17SQLO_SLATCH_CAS6411getConflictEm +
0x007c
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05363F6F _ZN12sqlpValLotch12getLatchOnlyEmPKcm +
0x016f
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05454E18
_Z21sqlbLatchPoolR_inlineP12SQLB_POOL_CBibiPKc + 0x00b8
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05BC1799 _Z25sqlbLatchPoolForReadWriteP12SQLB_POOL_CB
+ 0x0029
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05DEC71E
_Z13sqlbUpdateMRTtP9SQLP_LSN8PmP12SQLB_GLOBALS + 0x00ee
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0605E6D3
_Z8sqldmpndP8sqeAgentiPcP9SQLP_LSN8PmP15SQLD_RECOV_INFO + 0x0c23
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B3D8518 _Z8sqlptpplP8sqeAgentiPb + 0x0668
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B3BBEBF _Z8sqlpxcm1P8sqeAgentP15SQLXA_CALL_INFOi +
0x042f
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B96447F
_Z12sqlrrcom_dpsP8sqlrr_cbiiP15SQLXA_CALL_INFO + 0x165f
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B961FE0 _Z8sqlrrcomP8sqlrr_cbii + 0x0550
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B93A176 _Z12sqlrr_commitP14db2UCinterface + 0x0136
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD09A8E1E8
_Z16sqljs_ddm_rdbcmmP14db2UCinterfaceP13sqljDDMObject + 0x0228
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
...
At the same time, prefetchers are waiting behind the writer
agent on the latch SQLO_LT_SQLB_POOL_CB__readLotch in S mode in
the following stack:
-----FUNC-ADDR---- ------FUNCTION + OFFSET------
0x00007FCD0390CCA6
_Z25ossDumpStackTraceInternalmR11OSSTrapFileiP7siginfoPvmm +
0x0356
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0390C8EB ossDumpStackTraceV98 + 0x002b
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD03908AD7 _ZN11OSSTrapFile6dumpExEmiP7siginfoPvm +
0x00d7
(/home/db2mcys/sqllib/lib64/libdb2osse.so.1)
0x00007FCD0B170187 sqlo_trce + 0x03c7
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B2DBC0B sqloDumpDiagInfoHandler + 0x020b
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD12E71680 address: 0x00007FCD12E71680 ; dladdress:
0x00007FCD12E62000 ; offset in lib: 0x000000000000F680 ;
(/lib64/libpthread.so.0)
0x00007FCD02917337 semop + 0x0007
(/lib64/libc.so.6)
0x00007FCD0B16E3A2 _ZN17SQLO_SLATCH_CAS6418getConflictComplexEm
+ 0x07e2
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B16DBBC _ZN17SQLO_SLATCH_CAS6411getConflictEm +
0x007c
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05363F6F _ZN12sqlpValLotch12getLatchOnlyEmPKcm +
0x016f
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05454E18
_Z21sqlbLatchPoolR_inlineP12SQLB_POOL_CBibiPKc + 0x00b8
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05B9824B
_Z25sqlbReadAndReleaseBuffersP16SQLB_OBJECT_DESCjmmmP11SQLB_pfMi
sc + 0x02bb
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05B9B9F7
_Z22sqlbServiceListRequestP11SQLB_pfMiscP16SQLB_OBJECT_DESCPjj +
0x04b7
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05B95C17
_Z26sqlbPFPrefetcherEntryPointP16sqbPrefetcherEdu + 0x1227
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD05B94964 _ZN16sqbPrefetcherEdu6RunEDUEv + 0x0024
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0CDB321E _ZN9sqzEDUObj9EDUDriverEv + 0x01be
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD0B2D96BA sqloEDUEntry + 0x057a
(/home/db2mcys/sqllib/lib64/libdb2e.so.1)
0x00007FCD12E69DD5 address: 0x00007FCD12E69DD5 ; dladdress:
0x00007FCD12E62000 ; offset in lib: 0x0000000000007DD5 ;
(/lib64/libpthread.so.0)
0x00007FCD02915B3D clone + 0x006d
(/lib64/libc.so.6) |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 11.1 Module 4 Fix Pack 5 *
**************************************************************** |
| Local Fix: |
db2set DB2BPVARS=
in the config file, have this line:
NOREADVBCKUP=1
Note that this might have performance impact on the backup |
| Solution |
|
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner :
follow-up : IT30784 |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 31.01.2019
31.10.2019
31.10.2019 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
