IZ33919: STMM CANNOT TUNE DATABASE MEMORY FOR MULTIPLE DATABASES ON DB2 V ERSION 9.5 ON HP

DB2 Version 9.5 Fix Pack 4  for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 4a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• DB2 extended the capability to self-tune database memory to all
  platforms on version 9.5.  This capability is enabled by default
  for new 9.5 systems, and is the case when SELF_TUNING_MEM is ON
  and DATABASE_MEMORY = AUTOMATIC (these are both database
  configuration settings).
  
  HP is one of the platforms where this feature has been enabled
  on DB2 9.5, however it will not work for multiple databases.
  There is a problem where the STMM threads (one for each
  database) each try to attach to global shared memory, which
  cannot be done inside a single process.
  
  Here is a db2diag.log example showing the error:
  EDUID   : 61                   EDUNAME: db2stmm (STMM2)
  FUNCTION: DB2 Common, OSSe, OSSHIPCMemoryEx::attach, probe:70
  MESSAGE : ECF=0x9000000D=-1879048179=ECF_NO_MEMORY
            Insufficent memory
  CALLED  : OS, -, mmap
  OSERR   : ENOMEM (12) "Not enough space"
  DATA #1 : Hex integer, 4 bytes
  0x00000003
  DATA #2 : Hex integer, 4 bytes
  0x00000001
  CALLSTCK:
    0 0xC0000000119723B0 ossLog + 0x610
    1 0xC000000011972A40 ossLogSysRC + 0x160
    2 0xC00000001197F200 _ZN15OSSHIPCMemoryEx6attachEPK25OSSIPCM
  emoryExAttachPar
  amP18OSSIPCMemoryExInfo + 0x11C0
    3 0xC00000002EFA3570 _Z15stmmAttachToShmP17stmmGlobalBenefit
   + 0x2D0
    4 0xC00000002EFA66D0 _Z16stmmGetDBMemDataPP21stmmCostBenefit
  RecordP19stmmDBM
  emTuningInfoP19stmmExternalBenefitP16sqeLocalDatabase + 0x430
  .
  Note that STMM is still able to tune the individual consumers
  within database_memory (bufferpools, package cache, etc.)
  

Local fix

• set DATABASE_MEMORY to an explicit value
  

Problem summary

• Users Affected: DB2 9.5 on HP platforms using STMM
  with DATABASE_MEMORY = AUTOMATIC
  
  Problem Description: See Error Description
  
  Problem Summary: See Error Description
  

Problem conclusion

• Problem was first fixed in Version 9.5 FixPack 4 (s090429).
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• STMM
  

Fix information

• Fixed component name

  DB2 UDB ESE HP-

• Fixed component ID

  5765F4103

Applicable component levels

• R950 PSN

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