Splunk AppDynamics automatically discovers JDBC backends based on host, port, URL, database, version and vendor values. To monitor all JDBC databases that contain "EC2" in their host names as a single database, create a JDBC custom discovery rule and use the following match condition: Host Contains "EC2" as shown in the following screen shot.

Summary	Rule Configuration

Assuming host names of the format "EC2-segment2-segment3", use the following naming configuration:

This configuration results in a single database icon on the flow map named "EC2".