DB2 - Problembeschreibung
Problem IC70077 | Status: Geschlossen |
ACCUMULATION OF DB2FMP (JAVA) WITH MEMORY CONSUMPTION WHEN KEEPFENCED=NO | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 | |
Problembeschreibung: | |
Output of "ps -elf | grep db2fmp" shows a large number of db2fmp (Java) processes running on your system when KEEPFENCED=NO. The db2fmp processes are not being reused and appear to be stale. For those db2fmp processes, the TIME value does not change between runs of the "ps -elf | grep db2fmp" command. The number of db2fmp processes may grow until virtual memory is exhausted. Issue "db2pd -fmp" and check the status flag for the 'stale' db2fmp processes. The flag value 0x80000003 for the problematic db2fmp processes means: 0x00000001 the db2fmp has a JVM -> used by Java routine + 0x00000002 the db2fmp is threaded -> for execution of threadsafe routines + 0x80000000 FMP will no longer be allowed to create new threads, either due to an explicit thread limit or reaching an internal resource limit ===================================== x80000003 Because your db2fmp is flagged as 0x80000003 you may see messages like the following in the db2diag.log file indicating that new threads cannot be created: 2010-05-24-16.56.12.520000-420 I8527H330 LEVEL: Warning PID : 4040 TID : 3552 PROC : db2fmp.exe INSTANCE: DB2 NODE : 000 EDUID : 3552 FUNCTION: DB2 UDB, routine_infrastructure, sqlerMasterThreadListener, probe:300 MESSAGE : Java heap is nearly full; no thread created 2010-05-24-16.56.12.520000-420 I8859H575 LEVEL: Warning PID : 2556 TID : 1564 PROC : db2syscs.exe INSTANCE: DB2 NODE : 000 DB : TEST APPHDL : 0-87 APPID: AC13240C.G77B.E57AE0955EF1 AUTHID : NIC EDUID : 1564 EDUNAME: db2agent (TEST) 0 FUNCTION: DB2 UDB, routine_infrastructure, sqlerMasterThreadReq, probe: 89 MESSAGE : FMP reported it could not create a new thread DATA #1 : Hexdump, 4 bytes 0x79E7E830 : C80F 0000 .... 2010-05-24-16.56.12.520000-420 I9436H456 LEVEL: Severe PID : 2556 TID : 1564 PROC : db2syscs.exe INSTANCE: DB2 NODE : 000 DB : TEST APPHDL : 0-87 APPID: AC13240C.G77B.E57AE0955EF1 AUTHID : NIC EDUID : 1564 EDUNAME: db2agent (TEST) 0 FUNCTION: DB2 UDB, routine_infrastructure, sqlerGetFmpThread, probe:20 RETCODE : ZRC=0xFFFFFBEE=-1042 | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ACCUMULATION OF DB2FMP (JAVA) WITH MEMORY CONSUMPTION * * WHENKEEPFENCED=NO * **************************************************************** * PROBLEM DESCRIPTION: * * Output of "ps -elf | grep db2fmp" shows a large number * * ofdb2fmp(Java) processes running on your system when * * KEEPFENCED=NO.Thedb2fmp processes are not being reused and * * appear to bestale.For those db2fmp processes, the TIME value * * does not changebetween runs of the "ps -elf | grep db2fmp" * * command. Thenumberof db2fmp processes may grow until * * virtual memory isexhausted.Issue "db2pd -fmp" and check the * * status flag for the 'stale'db2fmp processes. The flag value * * 0x80000003 for theproblematicdb2fmp processes * * means:0x00000001 the db2fmp has a JVM -> used by Java * * routine+ 0x00000002 the db2fmp is threaded -> for * * execution ofthreadsafe routines+ 0x80000000 FMP will no * * longer be allowed to create newthreads, either due to an * * explicit thread limit or reachinganinternal resource * * limit=====================================x80000003Because * * your db2fmp is flagged as 0x80000003 you may seemessages * * like the following in the db2diag.log fileindicatingthat new * * threads cannot be created:2010-05-24-16.56.12.520000-420 * * I8527H330 LEVEL:WarningPID : 4040 * * TID : 3552 PROC :db2fmp.exeINSTANCE: DB2 * * NODE : 000EDUID : 3552FUNCTION: DB2 UDB, * * routine_infrastructure,sqlerMasterThreadListener,probe:300MESS * : Java heap is nearly full; no thread * * created2010-05-24-16.56.12.520000-420 I8859H575 * * LEVEL:WarningPID : 2556 TID : 1564 * * PROC :db2syscs.exeINSTANCE: DB2 NODE : 000 * * DB : TESTAPPHDL : 0-87 * * APPID:AC13240C.G77B.E57AE0955EF1AUTHID : NICEDUID : 1564 * * EDUNAME: db2agent (TEST) 0FUNCTION: DB2 UDB, * * routine_infrastructure,sqlerMasterThreadReq,probe:89MESSAGE * * : FMP reported it could not create a new threadDATA #1 : * * Hexdump, 4 bytes0x79E7E830 : C80F 0000 * * ....2010-05-24-16.56.12.520000-420 I9436H456 * * LEVEL:SeverePID : 2556 TID : 1564 * * PROC :db2syscs.exeINSTANCE: DB2 NODE : * * 000 DB : TESTAPPHDL : 0-87 * * APPID:AC13240C.G77B.E57AE0955EF1AUTHID : NICEDUID : 1564 * * EDUNAME: db2agent (TEST) 0FUNCTION: DB2 UDB, * * routine_infrastructure,sqlerGetFmpThread,probe:20RETCODE : * * ZRC=0xFFFFFBEE=-1042 * **************************************************************** * RECOMMENDATION: * * WORKAROUNDS:1) Review your Java routines and ensure that the * * code is notheavily dependent on Garbage Collection. (e.g. * * close off theobjects manually after they are no longer used * * rather thenrelying on the JVM to clean them up)From the * * setting perspective2) If you use THREADSAFE Java routines * * (default), then setKEEPFENCED=YES. In that case we will * * reuse the same threadandreduce the chance of creating new * * threads.3) If you declare your routines as NOT THREADSAFE * * then youcanset KEEPFENCED to either YES or NO. When a * * routine is in aNOTTHREADSAFE mode, each routine will run in * * its owndb2fmp/JVM.If KEEPFENCED=NO a new fenced mode process * * is created anddestroyed for each fenced mode invocation. * * IfKEEPFENCED=YESthe existing db2fmp will be returned to the * * pool for reuse. * **************************************************************** | |
Local-Fix: | |
WORKAROUNDS: 1) Review your Java routines and ensure that the code is not heavily dependent on Garbage Collection. (e.g. close off the objects manually after they are no longer used rather then relying on the JVM to clean them up) From the setting perspective 2) If you use THREADSAFE Java routines (default), then set KEEPFENCED=YES. In that case we will reuse the same thread and reduce the chance of creating new threads. 3) If you declare your routines as NOT THREADSAFE then you can set KEEPFENCED to either YES or NO. When a routine is in a NOT THREADSAFE mode, each routine will run in its own db2fmp/JVM. If KEEPFENCED=NO a new fenced mode process is created and destroyed for each fenced mode invocation. If KEEPFENCED=YES the existing db2fmp will be returned to the pool for reuse. | |
verfügbare FixPacks: | |
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows | |
Lösung | |
APAR will be fixed in an upcoming v9.5 fixpak release | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC70081 Nachfolger : | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 21.07.2010 25.10.2010 25.10.2010 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.5. | |
Problem behoben lt. FixList in der Version | |
9.1.0.7 | |
9.5.0.7 |