When you upgrade the application server to a newer version, be aware of the following settings that you might want to change.
The Application Server JSF engine determines if the Sun Reference Implementation (RI) 1.2 or Apache MyFaces 2.0 is used from the Application Server run time. If either is used, the correct listener class is registered with the web container. You do not need to add the com.sun.faces.ConfigureListener or the org.apache.myfaces.StartupConfigureListener to your web.xml file.
To ensure the most successful migration, the return type of the StoredResponse getHeaderNames method was changed to com.ibm.websphere.servlet.response.CollectionEnumerationHybrid<String>. This type implements both Collection<String> and Enumeration.
When a SIP application sends a request to a SIP URI over Transport Layer Security (TLS) in version 6.1, the request URI scheme changes from "sip" to "sips." In the current version, the scheme does not change. You can reverse the new behavior by changing the application code. With a "sips" URI, the behavior remains the same after upgrading from version 6.1 to 7.0 or above. See the information center topic Premigration considerations for more information.
In Version 8.5.5.0 and later, if the web server plug-in receives an HTTPS request but cannot create an HTTPS transport to the application server, no connection is made. If you want to enable the web server plug-in to create an HTTP connection if an HTTPS connection cannot be made, specify the UseInsecure custom property. Creating an HTTP connection if an HTTPS connection cannot be made is less secure than creating no connection because the user might be unaware that their connection is no longer secure. By default in previous versions of WebSphere Application Server, if the web server plug-in receives an HTTPS request but cannot create an HTTPS transport to the application server, it creates an HTTP transport if one is defined. If an HTTP transport is not defined, no connection is made.