Reddit Engine

Project Overview

Rabbit Engine is an academic project developed as part of the COP5615: Distributed Operating Systems Principles course at the University of Florida (Fall 2024). The objective was to design and implement a highly concurrent backend system, inspired by Reddit, using the actor model architecture with Proto.actor in Go. The project features both HTTP and gRPC support for flexible multi-client and service connectivity.

What I Did:

• Designed and implemented a multi-layered backend architecture using Go and Proto.actor.
• Developed actors to encapsulate all core entities and actions (users, subreddits, posts, comments, authentication, and karma).
• Built a RESTful HTTP API and gRPC endpoints for communication between engine and clients.
• Leveraged SQL (SQLite) as a backend datastore and implemented a repository pattern for data abstraction.
• Created a client simulator to stress-test the system under various user and subreddit scenarios.
• Conducted extensive simulations to test scalability, concurrency, and fault tolerance.

What I Learned:

• Deepened understanding of the distributed actor model and its application in real-world concurrency problems.
• Gained practical experience with Proto.actor and Go’s concurrency primitives.
• Explored inter-process communication using protocol buffers (protobuf) and gRPC.
• Learned to design for scalability and reliability, including supervision trees and actor lifecycle management.
• Understood challenges in distributed state, coordination, and fault recovery.

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High-Level Architecture

flowchart TD
    subgraph Clients
        A1[Client 1]
        A2[Client 2]
    end
    subgraph Engine
      A1 -- gRPC --> C[Service]
      A2 -- gRPC --> C
      C --> D[Auth Actor Pool]
      C --> E[User Actor Pool]
      C --> F[Subreddit Actor Pool]
      C --> G[Post Actor Pool]
      C --> H[Comment Actor Pool]
      C --> I[Karma Actor Pool]
      D & E & F & G & H & I --> J[Database]
    end

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Setup and Running Instructions

Prerequisites

• Go 1.20+ installed
• (Optional) SQLite3 CLI for inspecting the database

Engine Setup

1. Clone the repository and navigate to the engine directory:

   git clone https://github.com/nitingoyal0996/reddit-engine.git
   cd reddit-engine/engine

2. Install dependencies:

   go mod tidy

3. Build the engine:

   go build -o reddit-engine

4. Run the engine:

   ./reddit-engine

Client Setup

1. Navigate to the client directory:

   cd ../client

2. Install dependencies:

   go mod tidy

3. Build the client:

   go build -o reddit-client

4. Run simulations (examples):

   ./reddit-client 1 1000         # Simulate 1000 user registrations/logins
   ./reddit-client 2 500 10       # Simulate Zipf subreddit distribution
   ./reddit-client 3 1000         # Simulate user connect/disconnect

   Note: Reset the database before each run to avoid test data conflicts.