Web application deployment troubleshooting tips

Web application deployment troubleshooting tips

Deployment of a web application is successful if we can access the application by typing a URL in a browser or if we can access the application by following a link. If we cannot access the application, follow these steps to eliminate some common errors that can occur during migration or deployment.

Web module migrated from version 4.x does not run in later WAS version.

IBM recommends using the High Performance Extensible Logging (HPEL) log and trace infrastructure . We view HPEL log and trace information using the logViewer .

Symptom Problem Recommended response
Your version 4.x web module does not run when we migrate it to v8.0 or later products. In version 4.x, the classpath setting that affected visibility was Module Visibility Mode. In versions 6.0 and later, we must use class loader policies to set visibility. Reassemble an existing module, or change the visibility settings in the class loader policies.
Refer to the Class loaders and Class loading articles for more information.

Welcome page is not visible.
Symptom Problem Recommended response
We cannot access an application with a web path of:
  /webapp/myapp
The default welcome page for a web application is assumed to be index.html. We cannot access the default page of the myapp application unless it is named index.html.

To identify a different welcome page, modify the properties of the web module during assembly. See the article, Assembling web applications, for more information.
HTML files are not found.
Symptom Problem Recommended response
Your web application ran successfully on prior versions, but now we encounter errors that the welcome page (typically index.html), or referenced HTML files are not found:
Error 404: File not found:
 Banner.html
Error 404: File not found:
 HomeContent.html
For security and consistency reasons, web application URLs are now case-sensitive on all operating systems.
Suppose the content of the index page is as follows:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 
5.0 Frameset//EN">
<HTML>
<TITLE>
Insurance Home Page
</TITLE>
    <frameset rows="18,80">
    <frame src="Banner.html"
           name="BannerFrame"
           SCROLLING=NO> 
    <frame src="HomeContent.html"
           name="HomeContentFrame">
    </frameset>
</HTML>
However the actual file names in the \WebSphere\AppServer\installedApps\... directory where the application is deployed are:
banner.html
homecontent.html
To correct this problem, modify the index.html file to change the names Banner.html and HomeContent.html to banner.html and homecontent.html to match the names of the files in the deployed application.
Proxy server cannot access a Web module

If we use the same context root when we install two applications that have the same Web module, and one of the applications is disabled. we are not able to use a proxy server to access the Web module. When this situation occurs, a 503 Service Unavailable error message is recoreded in the SystemOut and SystemErr logs.

We should use a different context root for the Web module in each application, or use an application server instead of a proxy server to access the Web module.bprac
For current information available from IBM Support on known problems and their resolution, see the IBM Support page.

IBM Support has documents that can save you time gathering information needed to resolve this problem. Before opening a PMR, see the IBM Support page.

Related:

Class loaders
Diagnose problems (using diagnosis tools)
Task overview: Securing resources
(ZOS) Deploy and administering enterprise applications
Class loading
Assembling web applications
(ZOS) JavaServer Pages troubleshooting tips
Web applications: Resources for learning
http://www.ibm.com/support/search.wss?rs=180&tc=SSEQTP&tc1=SSCR4XA