Web server plug-in problem determination guide for WebSphere Application Server V4 and V5 releases
 Technote (troubleshooting)
 
Problem(Abstract)
When accessing Web pages using the IBM® WebSphere® Application Server Web server plug-in, you might experience problems displaying the page. This can result in an HTTP error code, a network error code, or a no response error, among others. This document outlines common causes and solutions for these problems.
 
Resolving the problem
Most Web server plug-in problems fall under the following 3 categories:
  • HTTP error returned to the browser

  • Network error returned to the browser

  • No response returned to the browser – indefinite wait

  • HTTP error is returned back to the browser

    Quick checklist:


    • Try accessing the URL by connecting directly to the HttpTransport port of the Application Server (for example port 9080). If you cannot, this is probably not a plug-in problem. Make sure that the application has been correctly installed, the virtual host has been updated with the access port number and that you are entering the correct URL in the browser.

    • Make sure the Web server plug-in successfully installed. You can verify this by accessing a sample Web page such as the snoopservlet.

    • If the Web server is on a remote machine, make sure you have copied over the latest version of the plugin-cfg.xml file to the remote machine.
  • Network error is returned back to the browser

    Quick checklist:


    • Ping the Web server. Make sure that the machine is accessible on the network.

    • Ensure that the Web server is running. Perform a netstat and make sure that the Web server port is in listenmode. Make sure you are pointing the Web browser to the correct port.

    • Try accessing the URL by connecting directly to the HttpTransport port of the Application Server (for example port 9080). If you can access the resource using this method, this is probably a plug-in problem.

    • Ensure the DNS server is configured properly. Try accessing the page using the IP address instead of the hostname. Make sure that VirtualHost includes the hostname or IP address that you are trying to access.

      If, after going through the above suggestions, the problem still exists, browse the diagnostic logs such as http_plugin.log, access.log, error.log, SystemOut.log and SystemErr.log. Turn on tracing on the plug-in and HttpTransport components and browse the output.
  • No response comes back to the browser – “hung” requests

    Quick checklist:


    • Try accessing the HttpTransport port directly? If this does not work, it is not a plug-in problem. Some other system layer is failing

    • Ensure that the Application Server is not overloaded. Make sure that the Web container threads, CPU, memory, or other system resource is not fully consumed.

    • Is the Application Server hung? Is there a database deadlock, threads locked, or another similar condition?

      Refer to the whitepaper titled Understanding the WebSphere Application Server Web server plug-in at http://www-106.ibm.com/developerworks/websphere/library/
      techarticles/0310_cocasse/cocasse.html
      for debugging overloaded or hung systems.

If, after trying all the recommendations above, the problem still persists, refer to the following resources for more guidance:

WebSphere troubleshooting page:

Version 4.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/topic/
com.ibm.websphere.v4.doc/wasa_content/08.html


Version 5.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v5r1//topic/
com.ibm.websphere.nd.doc/info/ae/ae/welc_troubleshooting.html


Instructions to trace the WebSphere Application Server product code:

Version 4.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/index.jsp?topic=/
com.ibm.websphere.v4.doc/wasa_content/0803.html
(Version 4.0)

Version 5.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v5r1//topic/
com.ibm.websphere.nd.doc/info/ae/ae/utrb_traceservice.html


Interpreting the WebSphere Application Server trace output:

Version 4.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/topic/
com.ibm.websphere.v4.doc/wasa_content/0803.html#basic


Version 5.0:
http://publib.boulder.ibm.com/infocenter/wasinfo/v5r1//index.jsp?topic=/
com.ibm.websphere.nd.doc/info/ae/ae/ctrb_readtrc.html

Common Plugi-in Problems
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/index.jsp?topic=/
com.ibm.websphere.v4.doc/wasa_content/080501.html


HTTP Transport Technotes
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/index.jsp?topic=/
com.ibm.support.was40.doc/intro/mainTN_HTTP_Transport.html

Plugin Technotes
http://publib.boulder.ibm.com/infocenter/wasinfo/v4r0/index.jsp?topic=/
com.ibm.support.was40.doc/intro/mainTN_Plug-in.html
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Plug-in
Operating system(s): Windows
Software version: 5.1.1
Software edition:
Reference #: 1172115
IBM Group: Software Group
Modified date: Jul 29, 2008