Can javax.persistence.jdbc.url point to a remote database server?

In my persistence.xml file I put:

<property name="javax.persistence.jdbc.url" value="jdbc:mysql://link-to-my-database.us-east-1.rds.amazonaws.com:3306/TestDB"></property>

This points to my remote database server. But it seems to ignore this and instead GlassFish falls back to a default connection pool. Information on the subject is scarce. Everything uses a local connection yet doesn't specify you have to. Can I specify a remote JDBC URL for my database server? This question that I asked has led me here if you seek more information.