Here are the details from my web.xml:
Below is the servlet which we call through custom ajax call to get the JSON response. 
After pretty faces changes, its returning 404.

<servlet>
		<servlet-name>VizViewController</servlet-name>
		<servlet-class>com.cognizant.cloudone.ui.controller.VizViewController</servlet-class>
		<async-supported>true</async-supported>
		<load-on-startup>1</load-on-startup>
	</servlet>


	<servlet-mapping>
		<servlet-name>VizViewController</servlet-name>
		<url-pattern>/vizViewController</url-pattern>
	</servlet-mapping>



Since I am in the process of tesing, my pretty faces is very tiny:


<?xml version="1.0" encoding="UTF-8"?>
<pretty-config xmlns="http://ocpsoft.org/prettyfaces/3.3.3" 
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
               xsi:schemaLocation="http://ocpsoft.org/prettyfaces/3.3.3
               http://ocpsoft.org/xml/ns/prettyfaces/ocpsoft-pretty-faces-3.3.3.xsd">

    <url-mapping id="login">
        <pattern value="/lg" />
        <view-id value="/login/login.faces" />
    </url-mapping>
    <url-mapping id="dashboard">
        <pattern value="/db" />
        <view-id value="/dashboard/dashboard-overview.faces?isfirst=true" />
    </url-mapping>

</pretty-config>