Pal comes packaged with a series of self-test scripts. To run these, visit the web application root, and navigate to the self-test page. Inspect the result from each script - no errors should appear on the output.
You can carry out some checks immediately after deploying the webapp, as by default it comes with a Sample dataset .
You can check where the webapp is getting the configuration settings from by checking the webapp admin fingerprint page (see the navigations on the left of the webapp's pages).
The fingerprint page shows which configuration properties are being read from the JNDI values configured in the context file, and which properties are being read from the default.properties file shipped in the WAR file, or from a property file defined by yourself.
The dataservice web application contains simple web forms (see the navigation links on the main index page) to submit queries to the datacenter service.