Paxos Consensus Implementation

Overview

This project implements the Paxos consensus algorithm using Java, gRPC, and Java Swing. Multiple Proposers propose random values, and an Acceptor determines and distributes the consensus value (maximum). Originally designed for a web interface, it was adapted to Swing for simplicity.

Features

• Paxos consensus protocol
• gRPC-based server communication
• Real-time GUI visualization (Java Swing)

Prerequisites

• Java JDK 22+ (and java language 1.7)
• Maven
• IntelliJ IDEA (recommended)
• gRPC dependencies (managed via Maven)

Setup

git clone https://github.com/alimiheb/PaxosConsensusGUI.git
cd paxos-consensus
mvn clean install

Running

1. Start Proposers (in three terminals):

cd target
java -jar paxos-1.0-SNAPSHOT.jar 50051
java -jar paxos-1.0-SNAPSHOT.jar 50052
java -jar paxos-1.0-SNAPSHOT.jar 50053

2. Run Acceptor GUI in IntelliJ:

• Right-click PaxosAcceptor.java > Run 'PaxosAcceptor.main()'

Project Structure

src/main/java/rt4/paxos/
  - PaxosAcceptor.java
  - PaxosProposer.java
  - PaxosServiceImpl.java
  - PaxosVisualizer.java
src/main/proto/
  - paxos.proto
src/main/resources/
target/
pom.xml

Troubleshooting

Issue: "Cannot Resolve Symbol" Errors for gRPC Classes

After cloning the repository, you may encounter errors in IntelliJ IDEA such as Cannot resolve symbol 'PaxosServiceGrpc', Cannot resolve symbol 'ValueRequest', etc. This occurs because the gRPC-generated classes are not automatically recognized by IntelliJ IDEA.

Solution

1. Re-import the Maven Project:
   • In IntelliJ IDEA, open the Maven tool window (right sidebar).
   • Click the Reimport All Maven Projects button (circular arrow icon).
   • Alternatively, run the following command in the terminal:

     mvn idea:idea
     
     
     

Contact

For issues or feedback, open a GitHub issue or contact [iheb66alimi@gmail.com].