|
Problem IC64043
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Status: Closed |
LOAD PERFORMANCE PROBLEM ON WINDOWS IF THE CPU PARALLELISM APPLIED IS GREATER THAN 1 |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
When load cpu_parallelism > 1 is applied on load on the Windows
platform ( which is the default with a sufficiently sized
UTIL_HEAP_SZ and a multi CPU machine ), it is possible that
the load may not have optimal performance.
This is due to a particular spinlock algorithm applied by the
formatter processes in a load that may suffer from thread
starvation by the Windows process scheduler.
The problem can be diagnosed with the output of a db2trc
-perfcount -t data collection, showing excessive wait times in
the sqlulPutBuffer function call. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Windows multiple CPU ( >= 4 ) environments *
****************************************************************
* PROBLEM DESCRIPTION: *
* Load performance problem due to lazy system behaviour i.e. *
* system is mostly idle, but load performance is not as *
* expected. *
****************************************************************
* RECOMMENDATION: *
* Upgrade the database server to V9.5 Fix Pack 5 *
**************************************************************** |
| Local Fix: |
In some cases the Windows scheduler behaves differently when
other single process/ multi threaded applications e.g. the
javaw.exe process started by the Control Center is started. This
then appears to avoid the thread starvation in the load agents. |
| available fix packs: |
DB2 Version 9.7 Fix Pack 1 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
This problem was fist fixed in V9.5 Fix Pack 5 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 22.10.2009
22.02.2010
22.02.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP5
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.1
|
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