Need help with Java web messaging app design
I’m planning to develop a real-time chat platform using Java enterprise technologies for the server side. The goal is to create something that works smoothly like popular email services with instant messaging features.
My main concerns are:
- Handling high user traffic without performance issues
- Choosing the right architectural approach for scalability
- Making sure the chat loads quickly and responds fast
What design patterns or frameworks would you recommend for this type of project? The application needs to support many concurrent users, so I want to make sure I pick the right foundation from the start.
Any suggestions on database choices or caching strategies would also be helpful.
Spring WebFlux with reactive streams works well for real-time messaging applications. My experience with WebFlux and WebSocket connections showed that the reactive model effectively manages backpressure, which is crucial for maintaining performance with thousands of concurrent connections. For storage solutions, using Redis for message queuing and session management, alongside PostgreSQL for the persistent chat history, proved beneficial. Implementing CQRS allowed for horizontal scaling of read replicas for chat history, while keeping write operations centralized. Additionally, I utilized Apache Kafka to facilitate message distribution across multiple server instances and adopted a two-tier caching strategy with Redis for active conversations and Caffeine for frequently accessed user data, significantly reducing the database load during peak usage.
what’s your expected user scale? hundreds or thousands of concurrent users? also, have you thought about websockets vs server-sent events for real-time features? that choice could shape your entire architecture. how comfortable are you with reactive programming?
Go with microservices - split your chat service, user management, and notifications into separate services. You can scale each piece independently when traffic hits. I’ve had good luck with WebSockets + Spring Boot, just don’t forget connection pooling and load balancing across instances.