GlobalProfileSync 🚀

Production-Grade Distributed Profile Synchronization System

A high-performance, resilient backend system designed for distributed Minecraft networks. This project demonstrates advanced Java engineering principles, focusing on event-driven architecture, thread-safety, and graceful degradation in high-concurrency environments.

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💎 Engineering Excellence

To meet the standards of top-tier US and European tech firms, this project implements several core architectural patterns:

• Service-Oriented Architecture (SOA): Business logic is decoupled from the platform API via a dedicated ProfileService, ensuring the system remains modular and framework-agnostic.
• Reactive Data Consistency: Leverages Redis Pub/Sub for real-time, cross-instance state synchronization with sub-millisecond latency.
• Circuit Breaker & Fallback Strategy: Implements a multi-layered persistence strategy. If the Redis cluster becomes unreachable, the system automatically triggers a YAML Fallback Layer, ensuring zero service interruption for end-users.
• Dependency Injection (DI): Strictly follows the Dependency Inversion Principle. By using constructor injection instead of static singletons, the codebase is highly testable and maintainable.
• Observability & Metrics: Built-in performance monitoring using LongAdder for high-concurrency metric tracking (Cache Hit/Miss ratios) to provide real-time system health data.

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🛠 Technical Stack

• Core: Java 8 (Optimized for Amazon Corretto / OpenJDK)
• Distributed Store: Redis (via Jedis High-Performance Pool)
• Persistence: YAML Fallback (Local Persistence Layer)
• Concurrency: Non-blocking I/O using CompletableFuture and ExecutorService
• Build System: Maven (Advanced Shading & Relocation)
• Quality Assurance: JUnit 5 & Mockito (Standard Mock-Maker-Inline)

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🏗 System Architecture

The project is structured to handle scale and failure as first-class citizens:

1. Distributed Write: When a profile is updated, the ProfileService persists data to the Redis Master node.
2. Event Broadcast: An update event is published to the distributed cluster via Redis Pub/Sub.
3. Local Invalidation: Online instances receive the event on a dedicated thread, invalidating or refreshing the local ConcurrentHashMap cache.
4. Resilience Layer: In the event of a Redis outage, the ProfileService intercepts the failure and redirects I/O to the FallbackStorage (Local Disk), maintaining data integrity until the cluster recovers.

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🧪 Quality & Testing

This project maintains high reliability through an automated testing suite:

• Unit Testing: Comprehensive logic validation using JUnit 5.
• Mocking: Advanced component isolation using Mockito, enabling the testing of services without requiring a live Redis environment.
• Resource Management: Validated connection pooling and thread-safe cleanup to prevent memory leaks in production.

# Run the professional test suite
mvn test