Gelly

Gelly is a graph API for Flink. In Gelly, graphs can be created, transformed, and modified. Gelly API provides all the basic and advanced functions of graph analytics. You can also select the different graph algorithms.

Gelly API

Gelly provides the API with the ability to take actions on graphs. We will discuss the API's in the follwing section.

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...