A fix is available
APAR status
Closed as program error.
Error description
Possible high other write I/O for insert or other sql update the page when the object is GBP-dependent. There is higher chance when uses MEMBER CLUSTER. In some case, OTHER WRITE I/O is possibly reported as OTHER READ I/O incorrectly.
Local fix
Remove the GBP-dependency might could help.
Problem summary
**************************************************************** * USERS AFFECTED: DB2 data sharing users. * **************************************************************** * PROBLEM DESCRIPTION: Performance degradation in data * * sharing, most noticeable with INSERT * * processing for MEMBER CLUSTER * * tablespaces. * * * * Performance is degraded due to hitting * * the Vertical Deferred Write Threshold * * (VDWQT) too frequently, causing the * * INSERT processing to be slowed down by * * I/O waits. * **************************************************************** * RECOMMENDATION: * **************************************************************** For DB2 V10, pages in GBP-dependent pagesets for which an X-mode page P-lock is held will be left on the Vertical Deferred Write Queue if the P-lock is kept after the page has been written. This is commonly done for spacemap pages in MEMBER CLUSTER table spaces. The presence of these pages on the VDWQ can cause writes to be scheduled more frequently due to the VDWQT being hit. However, the pages are not modified and so will not be written or removed from the VDWQ. This results is writes being scheduled frequently, in which only one or a few pages will be written. And since the pages currently being updated are likely to be written, the updating application may be slowed down by "other I/O" waits.
Problem conclusion
The logic which checks for the Vertical Deferred Write Queue Threshold being hit has been modified. It will now consider only modified pages, so as not to trigger writes inappropriately when few updated pages exist.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI07513
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
A10
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt
Submitted date
2013-12-05
Closed date
2014-02-24
Last modified date
2014-04-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI15429 UI15430
Modules/Macros
DSNB1CMS DSNB1LTS DSNB1LTX DSNB1SWS
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
Fix is available
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Document Information
Modified date:
02 April 2014