Table of Contents
How does Apache Giraph work?
Apache Giraph is real-time graph processing software that is mostly used to analyze social media data. Yahoo, Facebook and Twitter all are users of Giraph, tweaking the software to their own purposes. The software enables natural language-based relational searches that make social network data more informative.
What is an input and output of a vertex?
The input data contains a representation of the graph and, often, some metadata on the vertices or edges. The output data often consists of final vertex values, but can also contain the graph itself, possibly modified.
What is a directed graph?
A directed graph, also called a digraph, is a graph in which the edges have a direction. This is usually indicated with an arrow on the edge; more formally, if v and w are vertices, an edge is an unordered pair {v,w}, while a directed edge, called an arc, is an ordered pair (v,w) or (w,v).
What is meant by directed graph?
A directed graph (or digraph) is a set of nodes connected by edges, where the edges have a direction associated with them. For example, an arc (x, y) is considered to be directed from x to y, and the arc (y, x) is the inverted link. Y is a direct successor of x, and x is a direct predecessor of y.
How do you find Indegree and Outdegree on a graph?
Vertex ‘a’ has an edge ‘ae’ going outwards from vertex ‘a’. Hence its outdegree is 1. Similarly, the graph has an edge ‘ba’ coming towards vertex ‘a’. Hence the indegree of ‘a’ is 1….Example 2.
| Vertex | Indegree | Outdegree |
|---|---|---|
| e | 1 | 1 |
How do you find Indegree on a graph?
To find the in-degree of a vertex, just count the number of edges ends at the vertex. The Out-Degree of a vertex V written by deg+ (v), is the number of edges with v as the initial vertex. To find the out-degree of a vertex, just count the number of edges starting from the vertex.
How is GraphX different when compared to Giraph?
GraphX allows graphs to be read from Hive using an SQL-like query, allowing arbitrary column transformations. Giraph requires extra programming effort for such preprocessing tasks. Interacting with data in Spark (e.g., checking the output of a job) is convenient, though mostly when experimenting with small graphs.
What is GraphX Spark?
GraphX is a new component in Spark for graphs and graph-parallel computation. At a high level, GraphX extends the Spark RDD by introducing a new Graph abstraction: a directed multigraph with properties attached to each vertex and edge.
Which graphs are directed graphs?
What is directed graph and simple graph?
A directed graph or digraph is a graph in which edges have orientations. To avoid ambiguity, this type of object may be called precisely a directed simple graph. . Multiple edges, not allowed under the definition above, are two or more edges with both the same tail and the same head.
How do you find Indegree and Outdegree of vertices?
How do you find Indegree of adjacency list?
Let Adj[] be an array of size V where V=No. of vertices in a directed graph for representing adjacency list. Indegree of vertex u (u belongs to V) is actually the count of u in list Adj. because for calculating outdegree,we scan all vertices and under each vertices we scan all the edges of that vertices.