When Db2 is trying to rename an old inactive log file for reuse,
and the log file to be renamed is a truncated one (meaning its
size is smaller than the size as specified by the LOGFILSIZ
database configuration parameter), Db2 has to extend the file
to its full size before reusing it. The extension of the file
might take some time, during which the
SQLO_LT_SQLP_DBCB__sqlp_rename_sem latch is held. If
during this time, the writing to the current log file has
reached the end and needs to switch to a new file, the
switching to a new log file would be blocked by this latch.
This can cause a delay to transaction processing. The duration
is typically short and is determined by the time to grow the
truncated log file to its full size, so can be affected by the
LOGFILSIZ configuration.
Log file can become truncated by special operations such as
online backup, SET WRITE SUSPEND, ARCHIVE LOG command.
The stacks of the related EDUs:
== db2agent ==
0x00007FC36FC97180 sqloWaitThreshold + 0x0210
0x00007FC3701269A7
_Z27sqlpgWaitForLrecBufferLimitP14sqlpMasterDbcbm + 0x0357
0x00007FC36FEC914F
_Z14sqlpWriteToLogP8sqeAgentP11SQLP_TENTRYmmmP14SQLP_LREC_PARTP9
SQLP_LSN8Pm + 0x1f2f
0x00007FC36FEC647F
_Z11sqlpWriteLRP8sqeAgentmmmmmP14SQLP_LREC_PARTmP9SQLP_LSN8Pm +
0x198f
0x00007FC36AA45A33 address: 0x00007FC36AA45A33 ; dladdress:
0x00007FC36890A000 ; offset in lib: 0x000000000213BA33 ;
0x00007FC36AA445AE _Z10sqldAddRowP13SQLD_DFM_WORK + 0x013e
0x00007FC36AA3E70C _Z13sqldInsertRowP13SQLD_DFM_WORKi + 0x086c
== db2loggw ==
0x00007FC377992E9D __nanosleep + 0x002d
0x00007FC36FC2F20F sqloSpinLockConflict + 0x05cf
0x00007FC36FED7140
_Z19sqlpAddToRenameListP9SQLP_DBCBjPK9SQLP_LSN8PKjmb + 0x0160
0x00007FC36FFCC2C8
_Z16sqlpgOpenNextExtP9SQLP_DBCBmPP9SQLP_LECBmS3_ + 0x0a78
0x00007FC36FFD3091 _ZN11sqpLoggwEdu8sqlpgwlpEmmPK9SQLP_LSN8m +
0x2eb1
0x00007FC36FEFB128 _ZN11sqpLoggwEdu13sqlpLoggwMainEv + 0x1638
Waiting on latch type: (SQLO_LT_SQLP_DBCB__sqlp_rename_sem) -
Address: (0x7fc305c62df4), Line: 2296, File: sqlpRenameList.C
== db2loggr ==
0x00007FC36A32DBC4 pdtExit + 0x00f4
0x00007FC36FECE61E _Z18sqlpgExtendLogFileP9SQLP_DBCBP9SQLP_LECBj
+ 0x01ee
0x00007FC36FFC3CBB
_Z31sqlpgRenameFileDuringLogReclaimP11sqpLoggrEduP9SQLP_DBCBPP9S
QLP_LECBm + 0x019b
0x00007FC36FFC2FBA
_ZN11sqpLoggrEdu21sqlpLogReclaimRuntimeEP9SQLP_DBCBPb + 0x0d0a
0x00007FC36FF02777 _ZN11sqpLoggrEdu13sqlpLoggrMainEv + 0x2357
Holding Latch type: (SQLO_LT_SQLP_DBCB__sqlp_rename_sem) -
Address: (0x7fc305c62df4), Line: 1243, File: sqlpLogReclaim.C
HoldCount: 1
Holding Latch type: (SQLO_LT_sqlpPeriodicWorkState__pwsLatch) -
Address: (0x7fc305c71ce8), Line: 31, File:
/view/.../vbs/engn/include/sqlpdbcb_latched.h HoldCount: 1 |
