PM47654: POOR PERFORMANCE RESULTS FROM USING THE KEY FUNCTION IN AN XSLT STYLESHEET

8.0.0.2: WebSphere Application Server V8.0 Fix Pack 2
8.0.0.3: WebSphere Application Server V8.0 Fix Pack 3
8.0.0.4: WebSphere Application Server V8.0 Fix Pack 4
8.0.0.5: WebSphere Application Server V8.0 Fix Pack 5
8.0.0.6: WebSphere Application Server V8.0 Fix Pack 6
8.0.0.7: WebSphere Application Server V8.0 Fix Pack 7
8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15

APAR status

• Closed as program error.

Error description

• Each reference to the key function in an XSLT stylesheet
  results in performance that is proportional to the size of the
  input document.  Users expect the performance of the key
  function to be constant rather than increase with the size of
  the input.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: XSLT stylesheets that make extensive    *
  *                      use of the key function exhibit poor    *
  *                      performance.                            *
  ****************************************************************
  * RECOMMENDATION:  Install a fix pack that contains this       *
  *                  APAR.                                       *
  ****************************************************************
  The XSLT processor maintains the key table for an input
  document using a Java HashMap.  The processor attempts to
  compute the key tables for each input document one time by
  caching each key table, in turn, in another HashMap, using a
  document identifier as the key.  After computing the key
  table, the processor passes the HashMap containing the newly
  constructed key table and the cache HashMap to a method that
  stores the new key table in the cache HashMap.  However, the
  arguments to the method are reversed, so that the processor
  passes the key table HashMap in the argument position where
  the cache HashMap belongs, and the cache HashMap in the
  argument position where the key table HashMap belongs.
  This means that the processor never caches the newly
  constructed key table, and the next time the key function is
  referenced on a node in that same document, the key table for
  that document will be constructed again.
  

Problem conclusion

• The problem was resolved by swapping the two HashMap arguments
  in the call to the method that adds a newly constructed key
  table HashMap to the cache HashMap.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.0.0.2.  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:

  PM47426

• 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

• R800 PSY

     UP