PH16593: APPLICATION WITH DUPLICATE SERVLET-URL MAPPING FAILS TO DEPLOY IN VERSION 9

9.0.5.3: WebSphere Application Server traditional Version 9.0.5 Fix Pack 3

APAR status

• Closed as program error.

Error description

• WebSphere Application Server V9 implements Servlet 3.1. The
  Servlet 3.1 specification provided some clarifications. For
  example, more than one servlet cannot be mapped to the same URL.
   In WebSphere Application Server 8.5.5 an application with a
  duplicate servlet-url mapping deploys successfully. However, in
  Version 9, the application fails to deploy. An error message
  similar to the following is displayed in the SystemOut.log:
  
  
  
      [7/19/19 8:41:19:853 EEST] 00000001 webfragmerger E
  WebFragMergerImpl processExceptions Web fragment merge
  processing error [
  com.ibm.ws.webfragmerger.action.ServletFragMergeAction@db0c5540
  ]: (com.ibm.wsspi.webfragmerger.WebFragMergerException: Error:
  Web module [ WEB-INF/web_merged.xml ] maps URL [ < a url > ] to
  servlet [ < A Servlet > ]. The URL is already mapped to servlet
  [ < B Servlet >])
  

Local fix

• The fix causes the deployment code to ignore the duplicate
  servlet mapping. However, since the web_merged.xml is included
  in the application, a new one is not generated. This means the
  runtime (web container) code will still see the duplicate url
  mapping, which means we will need a fix from the web container
  team.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere                  *
  *                  Application Server 9.0 having an            *
  *                  application with multiple servlets mapped   *
  *                  to the same URL                             *
  ****************************************************************
  * PROBLEM DESCRIPTION: Application with multiple servlets      *
  *                      mapped to the same servlet fails to     *
  *                      deploy                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An application fails to deploy, and a message similar to the
  following is displayed in the SystemOut.log:
  [7/19/19 8:41:19:853 EEST] 00000001 webfragmerger E
  WebFragMergerImpl processExceptions Web fragment merge
  processing error [
  com.ibm.ws.webfragmerger.action.ServletFragMergeAction@db0c5540
  ]: (com.ibm.wsspi.webfragmerger.WebFragMergerException: Error:
  Web module [ WEB-INF/web_merged.xml ] maps URL [ < a url > ] to
  servlet [ < A Servlet > ]. The URL is already mapped to servlet
  [ < B Servlet >])
  WebSphere Application Server V9 implements Servlet 3.1. The
  Servlet 3.1 specification provided some clarifications. For
  example, multiple servlets cannot be mapped to the same URL.
  In WebSphere Application Server 8.5.5 an application with a
  duplicate servlet-url mapping deploys successfully. However, in
  Version 9, the application fails to deploy.
  

Problem conclusion

• There does not seem to be any value in having multiple servlets
  mapped to the same URL, as only one servlet will ever be
  accessed for a given URL.  In this case, the servlet which is
  actually accessed for the given URL is undefined.
  
  However, for the sake of backward compatibility and allowing
  such an application to continue to be deployed, a new custom
  property is created to allow the deployment to succeed.  Note
  that an existing property already allows such an application
  to start.
  
  IMPORTANT: To allow the application to deploy and start, you
  need to set the following property as both a JVM custom
  property and also as a WebContainer property.
  
  com.ibm.ws.webcontainer.servlet30compatibility = true
  
  To allow the application to deploy, set this property as a
  JVM custom property.  To set a JVM custom property, see the
  following instructions:
  
  https://www.ibm.com/support/knowledgecenter/en/SSEQTP_9.0.5/com.
  ibm.websphere.nd.multiplatform.doc/ae/xrun_jvm.html
  
  To allow the application to start, set the property as a
  WebContainer property.  To set a WebContainer property see the
  following instructions:
  
  https://www.ibm.com/support/knowledgecenter/en/SSEQTP_9.0.5/com.
  ibm.websphere.base.doc/ae/rweb_custom_props.html
  
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 9.0.5.3.  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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels

• R900 PSY

     UP