URL Shortener using Consistent Hashing with Sharded Database

A basic URL shortener that takes a URL, consistently hashes it and stores it in a sharded database using hash-ring (Chooses a DB connection from a pool based on the hashed URL).

HTTP Endpoints:

Returns JSON response

• POST : http://localhost:3000/?url=:url (url = url to shorten)
• GET : http://localhost:3000/:urlId (urlId = shortened URL)

Requirements:

• docker >= 17.12.0+
• docker-compose
• node.js
• npm

Node

• Node installation on Windows

  Just go on official Node.js website and download the installer. Also, be sure to have git available in your PATH, npm might need it (You can find git here).

• Node installation on Ubuntu

  You can install nodejs and npm easily with apt install, just run the following commands.

  $ sudo apt install nodejs
  $ sudo apt install npm
  

• Other Operating Systems

  You can find more information about the installation on the official Node.js website and the official NPM website.

If the installation was successful, you should be able to run the following command.

$ node --version
v8.11.3

$ npm --version
6.1.0

If you need to update npm, you can make it using npm! Cool right? After running the following command, just open again the command line and be happy.

$ npm install npm -g

Quick Start

• Clone or download this repository
• Go inside the directory
• Run this command to build docker file docker build -t pgshard .
• Run this command docker-compose up -d

Environments

This Compose file contains the following environment variables:

• POSTGRES_USER the default value is postgres
• POSTGRES_PASSWORD the default value is changeme
• PGADMIN_PORT the default value is 5050
• PGADMIN_DEFAULT_EMAIL the default value is pgadmin4@pgadmin.org
• PGADMIN_DEFAULT_PASSWORD the default value is admin

Access to postgres:

• localhost:5432
• Username: postgres (as a default)
• Password: changeme (as a default)

Access to PgAdmin:

• URL: http://localhost:5050
• Username: pgadmin4@pgadmin.org (as a default)
• Password: admin (as a default)

Add new servers in PgAdmin:

Create Server 1 - Shard 1

• Name shard1
• Host name/address postgres1
• Port 5432
• Username as POSTGRES_USER, by default: postgres
• Password as POSTGRES_PASSWORD, by default changeme

Create Server 2 - Shard 2

• Name shard2
• Host name/address postgres2
• Port 5432
• Username as POSTGRES_USER, by default: postgres
• Password as POSTGRES_PASSWORD, by default changeme

Create Server 3 - Shard 3

• Name shard3
• Host name/address postgres3
• Port 5432
• Username as POSTGRES_USER, by default: postgres
• Password as POSTGRES_PASSWORD, by default changeme

Starting the Node Application

• Change local machine hostname in index.js
• Make sure the databases are running
• In the current directory npm start