Fixes are available
DB2 Version 9.1 Fix Pack 7 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 7a for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 8 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 9 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 10 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12 for Linux, UNIX and Windows
APAR status
Closed as program error.
Error description
When performing an online parallel backup, the I/O activity will be done by the prefetcher processes. In the current algorithm, these can be seen as competing for the same resource when examining repeated stack traces of these processes during a backup process. A typical stack exposing this contention would show : getConflictComplex__17SQLO_SLATCH_CAS64FCUl + 0x244 getConflict__17SQLO_SLATCH_CAS64FCUl + 0xE0 @28@3@sqloltch_track__FCP10sqlo_latchCUlCPCcT2C14SQLO_LT_VALUES - 0x58 sqlbLatchPoolRange__FP12SQLB_GLOBALSUsUiT3PiT5ib + 0x334 sqlbDMSDirectRead__FP17SQLB_DIRECT_IO_CB + 0x14 sqlbDirectRead__FP17SQLB_DIRECT_IO_CB - 0x6C sqlbServiceDirectReadRequest__FP11SQLB_pfMisc + 0x6BC sqlbPFPrefetcherEntryPoint__FPcUi + 0x444 This apar reduces the resource latching needed and should hence improve throughput during the online backup. The impact of this problem depends on the speed of the backup media ( this is the bottleneck in most cases ). The speed of the offline backup with the same parameters is a reasonable measure of the fastest throughput that can be achieved, but online will always carry more overhead.
Local fix
n/a
Problem summary
Problem summary : suboptimal online backup performance due to internal latching contention Users Affected : all ( parallel ) online backup users Problem conclusion : this apar improves online backup performance
Problem conclusion
This problem was first fixed in v9.1 fixpak 7.
Temporary fix
Comments
APAR Information
APAR number
LI73100
Reported component name
DB2 UDE ESE LIN
Reported component ID
5765F4104
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-01-30
Closed date
2009-04-28
Last modified date
2009-04-28
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
DB2 UDE ESE LIN
Fixed component ID
5765F4104
Applicable component levels
R910 PSN
UP
R950 PSN
UP
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Document Information
Modified date:
28 April 2009