While deploying a BlazeDS project, I ran into a small problem that the META-INF/context.xml was not being loaded by tomcat.
The context.xml has a simple JNDI datasource defined
type="javax.sql.DataSource"
username="username"
password="password"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://yourhost.com:3306/dbname" />
Reading up on the tomcat docs it became obvious that tomcat was loading the Adobe BlazeDZ tomcat/conf/context.xml.