I wrote a testcase with embedded GlassFish for testing an EJB.
When I tried to test it using jdbc/mydb as datasource (in persistence.xml) I got the following error
Exception while preparing the app : Invalid resource : jdbc/mydb_pm com.sun.appserv.connectors. internal.api.ConnectorRuntimeException: Invalid resource : jdbc/mydb_pm
When I changed the datasource to jdbc/__default with the same connection pool as of jdbc/mydb it worked perfect.
Why is it so? What is the difference between these two datasources?