Yes! Your datasource is not registered in Tomat.
Also look into the documentation http://tomcat.apache.org/tomcat-6.0-doc/config/context.html
Did you modify the contents of context.xml for the web application (i.e, gwt-console-server)? or modified in
$CATALINA_BASE/conf/context.xml file where the Context element information will be loaded by all webapps?
What are the conents of context.xml?