How do you configure Tomcat 6 for use Oracle Dataguard? We have one physical database in site1 up and one physical database in site2 down.
The Data Guard configuration is something you do on the Oracle server itself. For the Oracle Dataguard documentation online go here: http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/toc.htm
How the application accesses this is by using Oracle's JDBC driver. This you configure as a JNDI resource, and using Oracle's configuration.