msgQ

📨 msgQ is a lightweight in-memory message streaming service supporting multiple topics, producers, and consumers. It ensures message order within partitions, offers thread safety, and enables real-time data streaming for local environments and testing scenarios.

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⚙️ Features

🧵 Topics

• ✅ Create new topics with configurable number of partitions
• ✏️ Edit topics
• ❌ Delete topics

🏭 Producers

• 📤 Publish messages to topics
• 🔁 Partitioning based on key:

  int partitionIndex = key.hashCode() % partitionCount;

🙋 Consumers

• 🔔 Subscribe and unsubscribe to specific topics
• 📥 Consume messages from assigned partitions
• 📌 Tracks offset for each consumer per partition to avoid reprocessing

💬 Messages

• 🧾 Messages are composed of a key and a payload
• 🔄 Messages are ordered within the same partition

🚀 Concurrency & Thread Safety

• Supports multiple producers and consumers concurrently
• Internally synchronized structures for safe concurrent access

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🧠 Design Overview

                      +--------------------------+
                      |      Topic: payments     |
                      |      (3 partitions)      |
                      +--------------------------+
                        |         |         |
                        ▼         ▼         ▼
                      [P0]      [P1]      [P2]
                        |         |         |
      ┌─────────────────┘         |         └─────────────────┐
      ▼                           ▼                           ▼
[Consumer A]                [Consumer B]                 [Consumer C]
(Offset per P0)            (Offset per P1)              (Offset per P2)

• Partitions allow parallelism.
• Each consumer reads from its offset, maintaining idempotent behavior.
• Producers are not aware of consumers, following decoupled pub-sub architecture.

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📦 Getting Started

Requirements

• Java 17+
• Maven (for building)

Clone the Repository

  git clone https://github.com/starreh-w0w/msgQ.git
  cd msgQ

Run

You can use Demo class interact with topics, producers, and consumers.

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📌 Use Cases

• 🛠️ Local development mock for Kafka-style systems
• 📊 Event-driven architecture simulations
• 📚 Educational purposes for understanding pub-sub, queues, offsets

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🛠️ Roadmap

• Persistent storage (e.g., WAL, disk)
• Message TTL / expiry support
• Dead-letter and retry queues
• Web dashboard for message and topic visualization
• Consumer groups and message rebalancing

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🤝 Contributing

Contributions, issues and feature requests are welcome!
Feel free to check the issues page.

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📄 License

Distributed under the MIT License. See LICENSE for more information.

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👨‍💻 Author

Made with ❤️ by Tyrant

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Inspired by Apache Kafka, designed for simplicity and local use-cases 🚀