org.neolumin.vertexium:vertexium-accumulo-iterators (maven):  Vertexium is an API to manipulate graphs, similar to blueprints. Unlike blueprints, every Vertexium method requires authorizations and visibilities. Vertexium also supports multivalued properties as well as property metadata. The Vertexium API was designed to be generic, allowing for multiple implementations. The only implementation provided currently is built on top of Apache Accumulo for data storage and Elastic Search for indexing. 
Keywords: accumulo|elasticsearch|graph-database|java