|
Problem IT04326
|
Status: Closed |
PACKAGE CACHE MEMORY USE CAN EXCEED CONFIGURED SIZE RESULTING IN MEMORY EXHAUSTION ON DB2 Cancun Release 10.5.0.4. |
| product: |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 |
| Problem description: |
This package cache memory problem is specific to DB2 Cancun
Release 10.5.0.4 (also known as Fix Pack 4).
When the size of the package cache reaches its configured limit
and new entries in the package cache are needed, DB2 will evict
older entries in order to maintain the size at the configured
limit. With this APAR, under certain timing conditions, if the
size limit is reached, rather than evicting older entries, the
package cache may exceed its configured limit and continue to
grow. This can result in the package cache unexpectedly
consuming additional database memory or instance memory.
This condition can be detected by issuing:
db2pd -db <dbname> -mempools
and determining if the logical size of package cache heap
significantly exceeds the configured size. In the output of
this command, the logical size is indicated by the LogSz column,
and the configured size is indicated by the CfgSize column. The
package cache is identified by the PoolName 'pckcacheh'.
An example output of this command is:
Memory Pools:
Address MemSet PoolName Id SecondId Overhead
LogSz LogHWM PhySz PhyHWM CfgSize Bnd
BlkCnt CfgParm
0x0000005AA9F520E8 CBLU5 pckcacheh 7 0 2929472
1363319099 1466382434 1569652736 1597964288 1769472 No
575359 PCKCACHESZ
In this example, the package cache has a configured size of
1769472 bytes but a larger logical size of 1363319099 bytes,
thus an indication of the APAR. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 for LUW version 10.5.5 *
**************************************************************** |
| Local Fix: |
Executing the FLUSH PACKAGE CACHE DYNAMIC statement will remove
unused dynamic SQL from the cache, thereby freeing up space. If
the workload is predominantly dynamic SQL, then periodically
issuing FLUSH PACKAGE CACHE can effectively provide relief by
keeping the size of the package cache below the configured
limit.
A special build (packaged as universal fix pack image) with the
fix for this APAR (based on DB2 Cancun Release 10.5.0.4) is
available for download from Fix Central at the following
location:
http://www.ibm.com/support/fixcentral/swg/quickorder?parent=ibm%
7EInformation%2BManagement&product=ibm/Information+Management/DB
2&release=10.5.*&platform=All&function=aparId&apars=IT04326&sour
ce=fc |
| Solution |
Fixed in DB2 for LUW version 10.5.5.
A special build (packaged as universal fix pack image) with the
fix for this APAR (based on DB2 Cancun Release 10.5.0.4 (also
known as Fix Pack 4) ) is available for download from Fix
Central at the following location:
http://www.ibm.com/support/fixcentral/swg/quickorder?parent=ibm%
7EInformation%2BManagement&product=ibm/Information+Management/DB
2&release=10.5.*&platform=All&function=aparId&apars=IT04326&sour
ce=fc |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 10.09.2014
13.03.2015
13.03.2015 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 10.5.0.5
|
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