DB2 - Problembeschreibung
Problem IT03173 | Status: Geschlossen |
PARALLEL-ENABLED QUERY EXECUTION MAY ALLOCATE EXCESSIVE APPLICATION HEAP MEMORY FOR REBAL OPERATOR | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problembeschreibung: | |
Excessive application heap memory usage may be seen on systems with query parallelism enabled (INTRA_PARALLEL = YES or other methods). This is due to an accounting logic error when tracking memory usage for the REBAL operator, which rebalances work between subagents working for the query. This is not a memory leak, as the memory will be freed at the end of query execution. Some systems may experience severe symptoms such as paging and/or memory exhaustion. Application Heap memory usage can be monitored using the MON_GET_MEMORY_POOL routine or db2pd -alldbs -mempools. If very high usage levels are seen which deplete available system or instance memory, the problem can be confirmed checking for high allocations from file source of 1984253944. db2pd -alldbs -memblocks appl 1 sort Memory blocks sorted by size for apph pool: PoolID PoolName TotalSize(Bytes) TotalCount LOC File 1 apph 69551569 87865 1057 1984253944 ... | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * Systems using query parallelism (typically with * * intra_parallel set to YES) * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 10.5 Fix pack 5 * **************************************************************** | |
Local-Fix: | |
An internal registry variable can be used to disable the REBAL OPERATOR db2set DB2_COMPILER_SMP_OVERRIDES=1 This setting requires recycling the db2 instance (db2stop/db2start). The setting should be removed db2set DB2_COMPILER_SMP_OVERRIDES= after upgrading to a level containing the APAR fix | |
Lösung | |
Problem first fixed in DB2 Version 10.5 Fix pack 5 | |
Workaround | |
see Local Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 15.07.2014 19.01.2016 19.01.2016 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.5.0.5 | |
10.5.0.7 |