Multithreaded Key-Value Store using RPC and 2PC

Overview

This project demonstrates a multi-threaded client-server application built with Java RMI (Remote Method Invocation) that allows multiple clients to perform operations (GET/PUT/DELETE) on a cluster of 5 key-value replicas concurrently. It implements a two-phase commit (2PC) protocol to ensure consistency across the replicas during write operations.

Features

• Remote Operations: Java RMI
• Concurrency: Multi-threaded request processing with thread pool
• Thread Safety: ConcurrentHashMap for thread-safe operations
• Two-Phase Commit: Atomic operations to ensure consistency across replicas
• Request Tracking: Request IDs to track communications
• Logging: Comprehensive logging for each class in their own log files

Requirements

• Java 17 or higher

• Maven for dependency management

• Dependencies (included in pom.xml):

  • Apache Commons CLI (1.9.0) - Command line argument parsing
  • Apache Commons Validator (1.7) - IP address validation

How to Build

With IntelliJ

1. Open current directory as a new Project in IntelliJ
2. Right-click on the src folder and select Mark Directory as > Sources Root.
3. Build the project by selecting Build > Build Project from the menu.

With Terminal

• Build with Maven using below command

  mvn clean package
  

How to Run

With IntelliJ

1. Start the Server: Open the Server file, then click ▶️ on the top right.
2. Start the Client: Open the Client file, then click ▶️ on the top right.
   • To perform a test run, specify -test flag in the argument. Click Current File when having Client open > select ⋮ > Run with Parameters > fill in argument
3. Inspect logs: Once the server and client are finished, log files for each class will be saved in the /log folder in the current directory.

With Terminal

1. Start the server

   java -cp target/kvstore.jar Server
   

2. Start the client

   java -cp target/kvstore.jar Client [-test]
   

Usage

Interact with the KV store using the following protocol in the client's terminal:

PUT key value
GET key
DELETE key

Other Notes

• Default connection to RMI registry is using localhost 127.0.0.1 from port 1099 to 1103.