When I last looked at agamemnon, it was not part of the globusonline.org project.
Nor do I recall support for RDF or the extended example of how to use it with your code.
Sorry, agamemnon, for those of you who don”t recall, is a library that enables you to use Cassandra as graph database.
Think about the speed and scalability of Cassandra for a moment and you will see the potential for such a matchup.