|
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 |
|
|
|
|
|
|