|
Problem IC84967
|
Status: Closed |
DB2 Private Memory leak in DB2 9.7 FP6 triggered by use of db2ReadLog API in applications (common in replication solutions) |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
When using DB2 Version 9.7 Fix Pack 6, Memory is consumed
quickly in the DB2 private memory when an application uses the
db2readlog API to extract log records (common in replication
solutions). This leads to a severe memory leak.
On DB2 Version 9.7 Fix Pack 6, private memory usage grows
quickly on the DB2 server ( db2sysc or db2syscs.exe process )
when applications are initiating log read requests through the
db2ReadLog API.
There may be a wide variety of symptoms such as;
out of instance memory,
STMM detuning,
system paging, hangs or failover.
An example of an application using the db2readlog api is IBMﾩ
Infosphereﾩ Replication Server (Data propagator). There maybe
other IBM or 3rd party 'Log reader' type applications which also
uses this API.
This problem was first introduced in DB2 Version 9.7 Fix Pack 6
(9.7.0.6)
To identify if you are hitting the issue:
Verify the DB2 Fixpack level by running the db2level command
to ensure you are on DB2 9.7 Fix Pack 6
2. Ensure that you are running an application that uses the
db2readlog API to extract the LOG records. Application snapshot
returns the application name. Example of applications using the
db2readlog API are bg_realtime_server, asncap.
Example of Application name as seen in the application snapshot
ouput:
Application name = ASNCAP.exe
3. If you notice the system memory usage grows quickly, perform
the following diagnosis to confirm you have encountered this
issue:
a) Gather application snapshots and verify if "Other Memory" is
high (i.e. > 10MB) and is continuing to grow,
Example entry as follows:
Memory Pool Type = Other Memory
Current size (bytes) = 719257600
High water mark (bytes) = 720764928
Configured size (bytes) = 8539602944
b) Gather db2pd -memb pid= output. It will show an increasing
number of allocations of size equal to LOGBUFSZ (database
configuration parameter) with the file hash reference 419169217
and location code 847 .
Example entry as follows:
Address DataAddress PoolID PoolName
BlockAge Size(Bytes) TID I LOC File
0x000000055D497FC8 0x000000055D497FE0 88 private
39046 4096000 4896 1 847 419169217 |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* If the system is running the initial version of 9.7 FP6 *
* (build number s120516 ) then upgrade to 9.7 FP6 build number *
* s120629 *
**************************************************************** |
| Local Fix: |
There is no Local Fix to the issue. |
| 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 |
First fixed in DB2 Version 9.7 Fix Pack 6 ( 9.7.0.6 ) dated
July.3.2012 Build number = s120629 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.06.2012
16.07.2012
04.09.2012 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.0.6,
9.7.FP6
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.7
|
 |
