PM59345: Updates to WebSphere Embedded Connect JDBC Driver in V6.1

6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server

APAR status

• Closed as program error.

Error description

• When using the WebSphere embedded connect JDBC driver shipped
  with WebSphere Application Server V6.1, the following two
  issues may be noticed.
  
  1)The temporary files(ddtb*.tmp) created by the WebSphere
  embedded connection JDBC driver are not cleared automatically.
  
  2)OutOfMemory issues are possible due to a leak in the JDBC
  driver classes.
  

Local fix

• Can use drivers from Microsoft
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server V6.1                                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: Upgrade the WebSphere embedded          *
  *                      connect JDBC Driver                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When using WebSphere embedded connect jdbc driver in V6.1, the
  following issues can be noticed.
  1)When accessing large fields of type BLOB using the embedded
  connect JDBC Driver, it starts creating ddtb*.tmp files with
  complete dump of column from SQL and those files does not get
  deleted from /tmp (in windows /temp) directory.
  2)The WebSphere embedded connect JDBC Driver classes
  namely BaseDatabaseMetaDataWrapper, BaseResultSetWrapper and
  BaseStatementWrapper arent getting Garbage Collected because
  they contain finalizers.
  When monitoring how the garbage collector responds to objects
  that are eligible to be gc'ed, those object that have class
  finalizers seem to be postponed and many times virtually
  ignored by the garbage collector.
  The reasoning behind this is that running the finalize() for
  objects is much more expensive and therefore the garbage
  collector can be more efficient and can reclaim more memory
  with less effort if it can relegate objects with finalizers to
  the last moment.  Most implementations of garbage collection
  run all finalize() methods in a single thread so there is no
  possibility of parallelism even on multi-core machines.
  To resolve this issue WebSphere embedded connect (data-direct)
  JDBC driver provides a mechanism whereby the applications can
  permit the drivers to create BaseDatabaseMetaDataWrapper,
  BaseResultSetWrapper and BaseStatementWrapper class instances
  which contain no "finalize" method.
  In order to obtain instances of these classes without
  finalizers, the app would need to specify the system property
  "DDTEK.includeFinalizers" with a value of false. This can be
  done by including the following to the JVM when it is
  launched: -DDDTEK.includeFinalizers=false
  Note that this should be specified only in environments in
  which the app is considered to be well-coded. That is, the app
  explicitly closes the objects it receives back from the
  driver. By default (if the system property is not specified),
  the drivers will create instances of those clases which DO
  contain finalizers. This is for purposes of backward
  compatibility
  This APAR upgrades the WebSphere embedded connect JDBC Driver
  to resolve the above two issues.
  

Problem conclusion

• The WebSphere adapter(RRA) component has been updated to
  include the latest version of the embedded connect jdbc driver
  that resolves the above two issues.
  The fix for this APAR is currently targeted for inclusion in
  fix pack 6.1.0.45.  Please refer to the Recommended Updates
  page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

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:

Fix information

• Fixed component name

  WEBSPHERE APP S

• Fixed component ID

  5724J0800

Applicable component levels

• R61A PSY

     UP

• R61H PSY

     UP

• R61I PSY

     UP

• R61P PSY

     UP

• R61S PSY

     UP

• R61W PSY

     UP

• R61Z PSY

     UP