Distributed Key-Value Store

Table of Contents

• Project Overview
• Features
• Setup and Installation
• Usage Guide
  • Starting a Server
  • Using the Client
• Visualization
  • System Architecture
  • Command Forwarding
  • Example Videos
• Example Scenarios
  • Scenario 1: Basic Operations
  • Scenario 2: Fault Tolerance and Recovery

Project Overview

This educational project demonstrates a distributed key-value store using raw TCP connections with Node.js and TypeScript. It is designed to help you understand the principles of distributed systems, low-level networking, and CLI-based interaction.

Features

• Distributed Architecture: Operates across three nodes to ensure data consistency.
• Command Support: Implements basic commands like GET, SET, UPD, and DEL.
• Node Failure Detection: Monitors and manages node failures with a heartbeat mechanism.
• Recovery Mechanism: Synchronizes recovered nodes with the rest of the system.
• CLI Tools: Provides command-line interfaces for both server management and client interactions.

Setup and Installation

1. Clone the Repository

   git clone https://github.com/your-username/distributed-key-value.git
   cd distributed-key-value

2. Install Dependencies

   npm install

Usage Guide

Starting a Server

To start a server, use the following command:

npm start

You will be prompted to choose which server instance to run.

Using the Client

To interact with a server, use the following command:

npm test

You will be prompted to select a server instance and then execute commands like SET, GET, UPD, and DEL.

Visualization

System Architecture

Diagram showing the overall architecture of the distributed key-value store system.

Command Forwarding

Diagram illustrating how the SET command is forwarded from Server A to other nodes.

Example Videos

Starting a Server

Screen recording of the CLI prompt for selecting and starting a server.

Sending Commands

Screen recording of the CLI interaction for sending commands to a server.

Example Scenarios

Scenario 1: Basic Operations

1. Start Server Instances:
   Run the servers using npm start for Server A, Server B, and Server C.

2. Set a Value Using Client CLI:
   Connect to Server A and execute the command:

   SET myKey myValue

   The SET command will be forwarded to Server B and Server C.

3. Get the Value:
   Execute the command to retrieve the value:

   GET myKey

   Confirm that myKey returns myValue from Server A, Server B, and Server C.

4. Update the Value:
   Update the value using the command:

   UPD myKey newValue

   Ensure that all servers reflect the updated value newValue.

5. Delete the Key:
   Execute the delete command:

   DEL myKey

   Verify that myKey is no longer present on Server A, Server B, and Server C.

Scenario 2: Fault Tolerance and Recovery

1. Start Server Instances:
   Ensure all server instances are running.

2. Simulate Node Failure:
   Stop Server B to simulate a failure.

3. Send Commands:
   Execute commands using the Client CLI and verify that Server A and Server C process them.

4. Restart the Failed Node:
   Restart Server B and check the recovery process.

5. Verify Recovery:
   Confirm that Server B resynchronizes with Server A and Server C and reflects the latest data.

6. Check Data Consistency:
   Ensure that all servers have consistent data after the recovery of Server B.