LamportLedger

This project implements a distributed blockchain ledger using Lamport’s mutual exclusion algorithm to manage client balances and ensure transaction integrity through transfer and balance operations.

Functionality

• Each client maintains a local balance table and a blockchain ledger recording all transactions.
• Clients also run a banking server that tracks all balances.
• To perform a transfer, a client acquires mutual exclusion using Lamport’s algorithm, verifies its balance, and updates the blockchain upon successful transfer.
• Transactions propagate to all clients, ensuring consistency across the distributed system.
• Balance inquiries are handled instantly using the local balance table without requiring mutual exclusion.

Implementation Details

• The Balance Table is a key-value store mapping client names to balances.
• Each client maintains a Lamport logical clock for ordering events.
• For transfer transactions:
  • The client executes Lamport’s mutual exclusion protocol.
  • If sufficient funds exist, the transaction is recorded in the blockchain and broadcast to all clients.
  • Each client updates its local balance table accordingly.
  • If insufficient funds exist, the transaction is aborted, and mutex is released.
• Balance queries directly read the local balance table without requiring mutex.

How to Run

1. Open three terminal instances.
2. Start each client using:

python3 client.py <clientnum>

3. The terminal will display available commands.