|
Problem IC72058
|
Status: Closed |
IN DPF SYSTEM, LOAD FROM CURSOR WITH LOBS LARGER THAN 32KB COULD CAUSE A MEMORY LEAK. |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
In DPF system, LOAD from CURSOR with LOBs larger than 32KB could
cause memory leak such as
PoolID PoolName TotalSize(Bytes) %Bytes TotalCount
%Count LOC File
5 utilh 592 52.86 4
4.76 968 sqlrkrpc.C
(in v97 it would be from the application heap instead of util
heap, such as
PoolID PoolName TotalSize(Bytes) %Bytes TotalCount
%Count LOC File
1 apph 1480 0.36 10
0.86 1077 sqlrkrpc.C
To detect the leak monitor a database partition other that the
coord partition. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All DB2 V9.1 and later versions performing a LOAD from *
* cursor in a DPF environment. *
****************************************************************
* PROBLEM DESCRIPTION: *
* In a DPF system running DB2 V9.1, 9.5 or 9.7 a LOAD from *
* CURSOR with LOBs larger that 32KB could cause *
* a memory leak in the utility heap (in V9.1) or application *
* heap (in 9.5 or 9.7) leading to increased memory usage on *
* the server. *
* *
* Secondary symptoms include: *
* - LOAD may fail with error SQL0973, out of utility heap. *
* - Degraded load/backup performance on v9.1 since load/backup *
* are basing resource usage on remaining utility heap. *
* - Increased system memory usage over time. *
* - Potential out-of-memory failures if any enforced limits *
* are reached. *
* *
* Depending on the DATABASE_MEMORY configuration setting, if *
* set to a fixed value, you may see the following message in *
* the db2diag.log file indicating out of memory errors for *
* utility heap. *
* *
* 2010-08-09-20.11.52.089542-300 E366984A702 LEVEL: *
* Warning *
* PID : 570528 TID : 1 PROC : *
* db2lfrm0 1 *
* INSTANCE: db2inst1 NODE : 001 DB : SAMPLE *
* APPHDL : 0-912 APPID: *
* 12.34.56.789.1234.100810000320 *
* AUTHID : USER1 *
* FUNCTION: DB2 UDB, SQO Memory Management, *
* sqloMemLogPoolConditions, probe:30 *
* DATA #1 : <preformatted> *
* Out of memory failure for Backup/Restore/Util Heap *
* (UTIL_HEAP_SZ) on node 1. *
* Requested block size : 34500 bytes. *
* Physical heap size : 551616512 bytes. *
* Configured heap size : 409600000 bytes. *
* Unreserved memory used by heap : 142016512 bytes. *
* Unreserved memory left in set : 0 bytes. *
* *
* The db2pd command can be used to identify the memory leak, *
* for example after the load from cursor is complete use the *
* db2pd command on a non-coordinator database partition : *
* *
* db2pd -dbp partition# -db <db_name> -memb 5 |grep 896367698 *
* *
* which should return output similar to *
* *
* Address PoolID PoolName BlkAge *
* Size(Bytes) I LOC File *
* 0x07800003166E0068 5 utilh 55174 42943 *
* 1 968 896367698 *
* *
* The hash ID 896367698 identifies the specific DB2 source *
* file. *
* *
* Or you can monitor memory usage in the utility heap and *
* observe an increasing pattern after the execution of each *
* LOAD, for example: *
* *
* db2pd -dbp partition# -db <db_name> -memp |egrep *
* "Address|utilh" *
* Address MemSet PoolName Id Overhead LogSz *
* LogUpBnd LogHWM PhySz PhyUpBnd PhyHWM *
* Bnd BlkCnt CfgParm *
* 0x07800002200012E0 SAMPLE utilh 5 0 352 *
* 20512768 352 65536 20512768 65536 *
* Ovf 2 UTIL_HEAP_SZ *
* *
* after the LOAD is complete issue again the same command *
* *
* db2pd -dbp partition# -db <db_name> -memp |egrep *
* "Address|utilh" *
* Address MemSet PoolName Id Overhead LogSz *
* LogUpBnd LogHWM PhySz PhyUpBnd PhyHWM *
* Bnd BlkCnt CfgParm *
* 0x07800002200012E0 SAMPLE utilh 5 0 648 *
* 20512768 6039059 65536 20512768 9568256 *
* Ovf 4 UTIL_HEAP_SZ *
* *
* You should observe increasing values in at least LogSz, *
* LogHWM and BlkCnt. *
* *
* Note that in DB2 9.5 and 9.7 the memory leak would be from *
* the application heap instead of utility *
* heap: *
* *
* db2pd -dbp partition# -db <db_name> -memb appctl |grep *
* 896367698 *
* *
* which should return output similar to *
* *
* Address PoolID PoolName BlkAge Size(Bytes) *
* I LOC File *
* 0x0700000010022208 1 apph 75 148 *
* 1 1025 896367698 *
* *
* Or you can monitor increasing memory usage in apph using the *
* -memp option like : *
* *
* db2pd -dbp partition# -db <db_name> -memp |egrep *
* "Address|apph" *
* Address MemSet PoolName Id Overhead LogSz *
* LogUpBnd LogHWM PhySz PhyUpBnd PhyHWM *
* Bnd BlkCnt CfgParm *
* 0x0700000010000868 AppCtl apph 1 0 6682 *
* 524288 6682 65536 524288 65536 *
* Phy 10 APPLHEAPSZ *
* 0x0700000010000720 AppCtl apph 1 0 10488 *
* 524288 11224 65536 524288 65536 *
* Phy 16 APPLHEAPSZ *
* 0x0700000010000490 AppCtl apph 1 0 13576 *
* 524288 85522 131072 524288 262144 *
* Phy 32 APPLHEAPSZ *
* *
* and after a load is complete execute the same command: *
* *
* db2pd -dbp partition# -db <db_name> -memp |egrep *
* "Address|apph" *
* Address MemSet PoolName Id Overhead LogSz *
* LogUpBnd LogHWM PhySz PhyUpBnd PhyHWM *
* Bnd BlkCnt CfgParm *
* 0x0700000010000868 AppCtl apph 1 0 6682 *
* 524288 6682 65536 524288 65536 *
* Phy 10 APPLHEAPSZ *
* 0x0700000010000720 AppCtl apph 1 0 10488 *
* 524288 11224 65536 524288 65536 *
* Phy 16 APPLHEAPSZ *
* 0x0700000010000490 AppCtl apph 1 0 13872 *
* 524288 86286 131072 524288 262144 *
* Phy 34 APPLHEAPSZ *
* *
* Monitor LogSz, LogHWM, and BlkCnt which should all increase *
* after each LOAD execution. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.7 Fix Pack 4. *
**************************************************************** |
| Local Fix: |
To work around the problem do not load from cursor. Load from a
file for example does not exhibit the same behavior. |
| available fix packs: |
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 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 |
The fix in included in DB2 Version 9.7 Fix Pack 4. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 20.10.2010
19.04.2011
19.04.2011 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP4
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.4
|
 |
