DB2 - Problembeschreibung
Problem IC78096 | Status: Geschlossen |
MEMORY LEAK IN UTILITY HEAP FROM AUTOMATIC STATISTICS COLLECTION | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
Automatic statistics collection might leak utility heap which can prevent utilities, such has BACKUP or LOAD, from running successfully. The available utility heap can eventually become exhausted which can cause major slowdown for utilities like backup. A typical db2diag.log message might show that no memory is available anymore: 2011-08-02-21.15.27.160426+120 E20761035A500 LEVEL: Info PID : 11337818 TID : 45492 PROC : db2sysc 0 INSTANCE: db2inst1 NODE : 000 DB : DB APPHDL : 0-20596 APPID: *LOCAL.db2inst1.110802191519 AUTHID : DB2INST1 EDUID : 45492 EDUNAME: db2agent (DB) 0 FUNCTION: DB2 UDB, database utilities, sqluxGetAvailableHeapPages, probe:926 DATA #1 : <preformatted> Autonomic BAR - heap consumption. Targetting (50%) - 8 of 0 pages. The following conditions must be met to encounter this problem: - AUTO_RUNSTATS or AUTO_STMT_STATS must be enabled (along with their parent database configuration parameters AUTO_MAINT and AUTO_TBL_MAINT) - automatic statistics collection performs a specific operation of writing statistics from the statistics cache to the catalogs, which is not an operation that occurs for every automatic statistics collection - the particular statistics written from cache to the catalogs include index statistics - problem started with DB2 V97, Fixpack 1 To determine if the leak is occuring check the following: - First, monitor utility heap usage with "db2pd -db <dbname> -memb 5 top", example: Top memory consumers in Database memory set: PoolID PoolName TotalSize(Bytes) %Bytes TotalCount %Count LOC File 5 utilh 80942160 99.13 17242 4.14 29303 793532624 5 utilh 311316 0.38 17242 4.14 29292 793532624 ... In this example you will see a growing pair of allocations (17242) for File value of "793532624". Typically these allocation will be the very top consumers if monitored over time. Note: the LOC values are fixpack release specific and might change. In the example above they are for fixpack 2 and fixpack 3a. Please consult with DB2 Services if you need further help for verification of this APAR. - Second, check the statistics logs (in $DIAGPATH/events/db2optstats.XXX.log") which should show asynchronous "WRITE" activity for table and index statistics, example: 2011-08-10-23.03.33.842509-240 E11897A527 LEVEL: Event PID : 2469964 TID : 1029 PROC : db2acd INSTANCE: db2inst1 NODE : 000 APPID : *LOCAL.db2inst1.110811030344 EDUID : 1029 EDUNAME: db2acd FUNCTION: DB2 UDB, Automatic Table Maintenance, JitsDaemon::runstats, probe:80 WRITE : TABLE AND INDEX STATS : Object name with schema : AT "2011-08-10-23.03.33.842304" : BY "Asynchronous" : success OBJECT : Object name with schema, 11 bytes DB2INST1.T1 IMPACT : None | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Problem Description above. * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 9.7 Fix Pack 5. * **************************************************************** | |
Local-Fix: | |
Set the following registry variable with the "-disable-hardening" value: db2set DB2_ATM_CMD_LINE_ARGS="-disable-hardening" If DB2_ATM_CMD_LINE_ARGS has already a value, like for SAP customers, expand the registry setting: db2set DB2_ATM_CMD_LINE_ARGS="-include-manual-tables -disable-hardening" Then instance restart is required. | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in Version 9.7 Fix Pack 5. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 12.08.2011 18.12.2011 18.12.2011 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP5 | |
Problem behoben lt. FixList in der Version | |
9.7.0.5 |