DB2 - Problem description
Problem IC72711 | Status: Closed |
PREFETCHERS AND PAGE CLEANERS LEAKING EVENT HANDLES ON WINDOWS | |
product: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problem description: | |
During a database deactivation, prefetchers and page cleaners are leaking Event handles on Microsoft Windows operating systems. The problem can be reproduced by connecting to a database followed by an immediate disconnect. Each prefetcher and page cleaner will be leaking exactly one Event handle, which can be monitored for example in Task Manager, or by using the !handle command in Windbg (Windows debugger). The !htrace command of Windbg will show two leaking code paths whose call stacks will be similar to this: 1) Page Cleaners ntdll!ZwCreateEvent+0x0000000c kernel32!CreateEventW+0x0000004b kernel32!CreateEventA+0x00000069 DB2SYS!sqloCreateEvent+0x00000ec6 DB2SYS!sqloInitIPCWaitPost+0x00000b41 DB2SYS!sqloInitEDUWaitPost+0x000000a2 DB2ENGN!sqloInitWaitPost+0x00000075 DB2ENGN!sqlpInitAgent+0x000001ce DB2ENGN!sqlbClnrInit+0x00000774 DB2ENGN!sqbPgClnrEdu::RunEDUInit+0x000000cb 2) Prefetchers ntdll!ZwCreateEvent+0x0000000c kernel32!CreateEventW+0x0000004b kernel32!CreateEventA+0x00000069 DB2SYS!sqloCreateEvent+0x00000ec6 DB2SYS!sqloInitIPCWaitPost+0x00000b41 DB2SYS!sqloInitEDUWaitPost+0x000000a2 DB2ENGN!sqloInitWaitPost+0x00000075 DB2ENGN!sqlpInitAgent+0x000001ce DB2ENGN!sqbPrefetcherEdu::RunEDUInit+0x0000021f DB2ENGN!sqzEDUObj::EDUDriver+0x00000162 Such Event handles will never be closed, which can potentially lead to a resource exhaustion if the database undergoes frequent deactivations. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Windows OS users * **************************************************************** * PROBLEM DESCRIPTION: * * See APAR text * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 UDB 9.7 FixPak 4 * **************************************************************** | |
Local Fix: | |
Ensure the database deactivation code path does not get executed too frequently, for example by activating the database explicitly using the ACTIVATE DB command, or ensuring that there is always at least one active connection to the database. | |
available fix packs: | |
DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows | |
Solution | |
See APAR text | |
Workaround | |
not known / see Local fix | |
BUG-Tracking | |
forerunner : APAR is sysrouted TO one or more of the following: IC72716 follow-up : | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 19.11.2010 28.04.2011 28.04.2011 |
Problem solved at the following versions (IBM BugInfos) | |
9.7. | |
Problem solved according to the fixlist(s) of the following version(s) | |
9.7.0.4 |