PK75090: NULLPOINTEREXCEPTION IN JSPEXTENSIONSERVLETWRAPPER.TRANSLATEJSP

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The problem occurs only in a WebSphere application server for
  z/OS running with multiple servants.  When JSPs are compiled on
  the fly in this environment, the runtime code manages the case
  where both servants may try to access a single JSP to compile it
  concurrently by allowing one servant to lock the JSP file while
  it compiles.  If the instance arises where two requests for a
  JSP needing to be compiled at the same time, and are routed to
  separate servant regions, the following NullPointerException is
  likely to occur:
  java.lang.NullPointerException
  at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
               translateJsp(JSPExtensionServletWrapper.java:404)
  at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
        _checkForTranslation(JSPExtensionServletWrapper.java:366)
  at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
        checkForTranslation(JSPExtensionServletWrapper.java:262)
  at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
        handleRequest(JSPExtensionServletWrapper.java:151)
  at com.ibm.ws.jsp.webcontainerext.JSPExtensionProcessor.
        handleRequest(JSPExtensionProcessor.java:255)
  at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(
                                                WebApp.java:3174)
  ...
  The above exception is thrown in the servant who is attempting
  to compile the JSP after another servant has already obtained
  a lock on the JSP file.  In addition to the NullPointerException
  the JSP in question is likely to be flagged as permanently
  unavailable for the life of the servant region, so that all
  requests coming to the servant for the JSP will fail with 500
  errors (UnavailableExceptions will be thrown to the client).
  

Local fix

• As a preventative measure, you can bypass this issue by
  precompiling JSPs before or during application deployment.
  If you find yourself currently experiencing
  UnavailableExceptions due to this issue, a recycle of the server
  or servant region will be required to recover from this problem.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere Application Server    *
  *                 V6.1 for z/OS                                *
  ****************************************************************
  * PROBLEM DESCRIPTION: When JavaServer Pages (JSP) are         *
  *                      compiling at runtime on a z/OS server   *
  *                      that is running with multiple           *
  *                      servants, a NullPointerException may    *
  *                      occur.                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem occurs only in a WebSphere z/OS server running
  with multiple servant regions.  When JSPs are compiled on the
  fly in this environment, the JSP Container manages the case
  where both servant regions may try to access a single JSP to
  compile it concurrently by allowing one servant to lock the
  JSP file while it compiles.  If the instance arises where two
  requests for a JSP need to be compiled at the same time, and
  are routed to separate servant regions, there is a small
  window in which a NullPointerException is likely to occur:
  java.lang.NullPointerException
  
  at
  com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.transl
  ateJsp(JSPExtensionServletWrapper.java:404)
  at
  com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper._check
  ForTranslation(JSPExtensionServletWrapper.java:366)
  at
  com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.checkF
  orTranslation(JSPExtensionServletWrapper.java:262)
  at
  com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.handle
  Request(JSPExtensionServletWrapper.java:151)
  ....................
  

Problem conclusion

• The JSP Container has been modified to cause a servant region
  to retry obtaining the lock on a JSP file before compiling it.
   This retry will expire after 120 seconds.  If the compilation
  time is expected to be longer, a user can increase the retry
  time by setting the webcontainer's custom property:
  
  com.ibm.ws.jsp.zosFileLockRetrying = 120 (default)
  
  The custom property is not case sensitive.
  
  Please refer to the following technote for instructions on
  enabling WebContainer custom properties:
  http://www.ibm.com/support/docview.wss?rss=180&uid=swg21284395
  
  APAR PK75090 requires changes to documentation.
  
  NOTE: Periodically, we refresh the documentation on our
  Web site, so the changes might have been made before you
  read this text. To access the latest on-line
  documentation, go to the product library page at:
  
  http://www.ibm.com/software/webservers/appserv/library
  
  The following Changes to the z/OS version of the
  WebSphere Application Server Version 6.1 Information
  Center.
  
  The following description of the
  com.ibm.ws.jsp.zosFileLockRetrying Web conatiner
  custom property will be added to the topic "Web
  container custom properties:"
  
  Extending the wait time when two servants need to
  concurrently compile the same JSP
  
  When JavaServer Pages files (or user-defined JSP files)
  are complied in an environment that has multiple servants,
  the JSP container uses locking to prevent both servants
  from trying to concurrently compile the same JSP file.
  If two requests for a JSP need to be compiled at the same
  time, and are routed to separate servants, the JSP
  container locks the JSP file until the compilation for
  the first servant completes. If the second servant has to
  wait for more than 120 seconds for the lock to be
  released, the request for the JSP fails.
  
  If you expect the compilation time for any of your JSP
  files to be more than 120 seconds, specify, in seconds,
  a value greater than 120 for the
  com.ibm.ws.jsp.zosFileLockRetrying custom property. The
  new setting should extend the wait time, such that the
  new wait time prevents a JSP request from failing in
  situations where two requests for the same JSP file need
  to be handled at approximately the same time, but the
  requests are routed to different servants.
  
  APAR PK75090 currently targeted for inclusion in Service
  Level (Fix Pack) 6.1.0.21 of WebSphere Application Server V6.1
  for z/OS.
  
  Please refer to URL:
  //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
  for Fix Pack availability.
  

Temporary fix

Comments

APAR Information

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

  PK69410

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

Modules/Macros

• BBGUBINF BBOUBINF
  

Fix information

• Fixed component name

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels

• R610 PSY UK41575

     UP08/11/26 P F811

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.