Practical Real-time Data Processing and Analytics

Graph representation

A graph is represented by a DataSet of Vertices and Edges. Graph nodes are represented by Vertex type. A vertex is defined by unique ID and value. A NullValue can be defined for a Vertex with no value. The following are the methods used for creating vertex in a graph:

Vertex<String, Long> v = new Vertex<String, Long>("vertex 1", 8L);Vertex<String, NullValue> v = new Vertex<String, NullValue>("vertex 1", NullValue.getInstance());

Graph edges are represented by edge type. An edge is defined by source ID (ID of source vertex), target ID (ID of target vertex), and optional value. The source and target IDs should be of the same type as the Vertex IDs. The following is the way to create an Edge in a graph:

Edge<String, Double> ...