|
Problem IC82182
|
Status: Closed |
A LOGIC ERROR IN STMM"S SORTHEAP RESERVATION TRACKING ARTIFICIALLY INCREASES STMM SORT TUNING |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
A logic error in STMM's tracking of throttled sort requests
results in a continuous upward trend in the enforced minimum
size for shared sort (SHEAPTHRES_SHR). This may cause other
STMM-tuned areas to be forced down, potentially causing
performance degradation or other resource issues (SQL1218).
This problem exists in:
Version 9.1 Fix Pack 6 and higher
Version 9.5 Fix Pack 2 and higher
Version 9.7 GA and higher
The following entry can be seen in STMM logs each time a
permanent increase is introduced (at DIAGLEVEL 3 or above)
FUNCTION: DB2 UDB, Self tuning memory manager,
stmmRegisterReserveSharedSortSpace, probe:3038
MESSAGE : Unexpected value in accounting of reserved sort memory
- 91545 - 1
- 5409 - 10641 - 0
Occasionally STMM may detect that the minimum size has grown
beyond a reasonable range, and may cap the minimum size, as
evidenced by the following STMM log entry (logged regardless of
DIAGLEVEL):
FUNCTION: DB2 UDB, Self tuning memory manager,
stmmComputeMinSHEAPTHRES, probe:837
MESSAGE : Unexpected minimum value for SHEAPTHRES_SHR - value
automatically
corrected - 299025 - 2076 - 342641 - 249120 - 96
- 0 -
96.000000 - 1 - 31 - 274113 - 735
The values are only maintained while the database is active, so
recycling the database will reset the minimum size to normal
values. Alternatively, use a fixed setting for SHEAPTHRES_SHR |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Systems where STMM is configured to tune SORT memory *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.7 Fix Pack 7 *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.7 Fix Pack 7 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 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
Problem first fixed in DB2 Version 9.7 Fix Pack 7 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 21.03.2012
30.10.2012
30.10.2012 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP7
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.7
|
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