JR26176: UNDER THE RARE CASES WHERE A DB2 APPLICATION CONTINUALLY LOADS AND UNLOADS DB2OSSE.DLL, HANDLES ARE LEAKED

APAR status

• Closed as program error.

Error description

• Under most circumstances, db2osse.dll does not exhibit any
  handle leaks because when the DB2 application that loaded
  db2osse.dll exits, the OS automatically cleans up and closes
  off the opened handles. Only in the cases where a DB2
  application stays running and it continually loads and unloads
  db2osse.dll will a handle leak result. An example of such an
  application would be one that creates/updates DB2 ODBC data
  sources. Each invocation of the ODBC API (such as
  SQLConfigDataSource()) will result in the OS loading and then
  unloading db2odbc.dll (which in turn loads/unloads
  db2osse.dll). Note: As soon as the application exits, however,
  the OS will close off all the opened handles.
  A DB2 application that stays running while continually loading
  and unloading db2osse.dll will result in handles being leaked
  and after some time, the system may become unstable because it
  starts to run out of resources.
  Using a handle viewing utility such as Process Explorer, the
  following seen as leaking:
  \BaseNamedObjects\SymGetModuleInfo-<pid>,
  \BaseNamedObjects\SymFunctionTableAccess-<pid>,
  \BaseNamedObjects\SymRegisterCallback-<pid>,
  \BaseNamedObjects\SymGetModuleBase-<pid>,
  \BaseNamedObjects\StackWalk-<pid>,
  \BaseNamedObjects\EnumerateLoadedModules64-<pid>,
  \BaseNamedObjects\SymGetSymFromAddr-<pid>,
  \BaseNamedObjects\SymInitialize-<pid>,
  \BaseNamedObjects\SymGetSearchPath-<pid>,
  \BaseNamedObjects\SymSetSearchPath-<pid>,
  \BaseNamedObjects\SymCleanup-<pid>,
  \BaseNamedObjects\SymGetOptons-<pid>,
  \BaseNamedObjects\SymSetOptons-<pid>,
  \BaseNamedObjects\GetTimestampForLoadedLibrary-<pid>,
  \BaseNamedObjects\ImagehlpApiVersion-<pid>,
  \BaseNamedObjects\ImagehlpApiVersionEx-<pid>,
  \BaseNamedObjects\SymLoadModule64-<pid>,
  \BaseNamedObjects\SymUnloadModule64-<pid>
  

Local fix

• Periodically close off and restart the DB2 application that is
  continually loading/unloading db2osse.dll. This will allow
  Windows to step in and clean up the leaked handles.
  

Problem summary

• UNDER THE RARE CASES WHERE A DB2 APPLICATION CONTINUALLY LOADS A
  ND UNLOADS DB2OSSE.DLL, HANDLES ARE LEAKED
  

Problem conclusion

• First Fixed in DB2 V8.1 Fixpak 16.
  

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:

  JR28450 JR28451

Fix information

• Fixed component name

  DB2 UDB ESE WIN

• Fixed component ID

  5765F4101

Applicable component levels

• R820 PSY

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