Apache Spark GraphX Describes Organizational Chart Easy

George Jen
3 min readFeb 2, 2020

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George Jen, Jen Tek LLC

GraphX is a 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.

GraphX includes a growing collection of graph algorithms and builders to simplify graph analytics tasks.

Here what I want to demonstrate is to use Graphx to describe an organizational chart, a most fundamental use case of graph computing.

Example:

Let’s define a simple org chart:

Let’s add one more person, sherry, Jack’s wife

First, I try it on a SQL database. I have PostgreSQL on my machine, therefore, use it:

Create 2 tables:

Vertex:

stores the id, name, title formation. Vertex stores the box or node

Edge:

Stores source id, destination id and relationship, Edge stores the line, or relationship

create table vertex

(id bigint,

property_name text,

property_title text

);

create table edge

(

src_id bigint,

dest_id bigint,

relationship text

);

Then add data into Vertex and Edge tables

The box:

Sherry, wife of owner

Jack, owner

George, clerk

Mary, sales

The line, indicates the relationship in the org chart:

Jack, owner is boss of George, clerk

Jack, owner is boss of Mary, sales

Sherry, wife of owner is boss of Jack, owner

George, clerk is coworker of Mary, sales

insert into vertex values (1,’Jack’,’owner’),(2, ‘George’, ‘clerk’), (3, ‘Mary’, ‘Sales’), (4, ‘Shrry’, ‘wife of owner’);

insert into edge values (1,2,’boss’), (1,3,’boss’), (2,3,’coworker’),(4,1,’boss’);

commit;

with x as (SELECT e.src_id, e.dest_id, e.relationship,

src.property_name src_name,

src.property_title src_title,

dst.property_name dest_name,

dst.property_title dest_title

FROM edge AS e LEFT JOIN vertex AS src ON e.src_id = src.id

LEFT JOIN vertex AS dst ON e.dest_id = dst.id)

select src_name || ‘, ‘ || src_title || ‘, is ‘

|| relationship || ‘ of ‘ || dest_name || ‘, ‘

|| dest_title description from x;

description

— — — — — — — — — — — — — — — — — — — — — — —

shrry, wife of owner, is boss of Jack, owner

Jack, owner, is boss of George, clerk

Jack, owner, is boss of Mary, Sales

George, clerk, is coworker of Mary, Sales

(4 rows)

Now switch to Spark GraphX with Scala code below:

import org.apache.spark._

import org.apache.spark.graphx._

import org.apache.spark.rdd.RDD

import org.apache.log4j._

import org.apache.spark.sql._

import org.apache.spark.graphx.{Graph, VertexRDD}

import org.apache.spark.graphx.util.GraphGenerators

Logger.getLogger(“org”).setLevel(Level.ERROR)

val spark = SparkSession

.builder

.appName(“graphx”)

.master(“local[*]”)

.config(“spark.sql.warehouse.dir”, “file:///tmp”)

.getOrCreate()

val sc=spark.sparkContext

val users: RDD[(VertexId, (String, String))] =

sc.parallelize(Array((1L, (“jack”, “owner”)), (2L, (“george”, “clerk”)),

(3L, (“mary”, “sales”)), (4L, (“sherry”, “owner wife”))))

val relationships: RDD[Edge[String]] =

sc.parallelize(Array(Edge(1L, 2L, “boss”), Edge(1L, 3L, “boss”),

Edge(2L, 3L, “coworker”), Edge(4L, 1L, “boss”)))

val defaultUser = (“”, “Missing”)

val graph = Graph(users, relationships, defaultUser)

val facts: RDD[String] =

graph.triplets.map(triplet =>

triplet.srcAttr._1 + “, “+ triplet.srcAttr._2 + “ is the “ + triplet.attr + “ of “ + triplet.dstAttr._1+”, “+triplet.dstAttr._2)

facts.collect.foreach(println(_))

Run the above scala code produces output below:

jack, owner is the boss of george, clerk

jack, owner is the boss of mary, sales

george, clerk is the coworker of mary, sales

sherry, owner wife is the boss of jack, owner

facts: org.apache.spark.rdd.RDD[String] = MapPartitionsRDD[20] at map at <console>:43

Summary:

If this is a complex chart, Spark Graphx is the perfect platform to compute the inter-relationships because of its distributed, in memory computing nature and rich GraphX computing library

The code used in this writing is in my github site:

https://github.com/geyungjen/jentekllc

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George Jen
George Jen

Written by George Jen

I am founder of Jen Tek LLC, a startup company in East Bay California developing AI powered, cloud based documentation/publishing software as a service.

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