WebSockets, SSE & Real-Time Systems
WebSockets, SSE (Server-Sent Events), and Real-Time Systems refer to technologies enabling instant, two-way or one-way communication between clients and servers. WebSockets establish persistent, full-duplex connections for interactive applications like chats or games. SSE allows servers to push updates to browsers over a single HTTP connection, suitable for live feeds. Real-Time Systems utilize these technologies to deliver timely, dynamic content, ensuring users receive information as events occur without manual refreshes.
WebSockets, SSE & Real-Time Systems
WebSockets, SSE (Server-Sent Events), and Real-Time Systems refer to technologies enabling instant, two-way or one-way communication between clients and servers. WebSockets establish persistent, full-duplex connections for interactive applications like chats or games. SSE allows servers to push updates to browsers over a single HTTP connection, suitable for live feeds. Real-Time Systems utilize these technologies to deliver timely, dynamic content, ensuring users receive information as events occur without manual refreshes.
💡 Key Takeaways
- Distinguish WebSockets and Server-Sent Events (SSE): bidirectional communication for interactive apps vs unidirectional server pushes for live updates.
- Explain how a WebSocket connection is established (handshake) and kept alive, including message framing and heartbeat/ping-pong.
- Identify real-time system design patterns (e.g., pub/sub, streaming) and how they impact latency, throughput, and scalability.
- Assess security and reliability considerations for real-time tech (TLS, authentication, reconnection handling, backpressure, and message sizing).
❓ Frequently Asked Questions
What is a WebSocket and how does it work?
A WebSocket is a persistent, full-duplex connection between client and server. After an HTTP handshake, it upgrades to a ws/wss connection, enabling real-time two-way data exchange with low latency.
What is Server-Sent Events (SSE) and when should you use it?
SSE is a unidirectional channel where the server pushes updates to the client over a long-lived HTTP connection. It’s ideal for live feeds and notifications when the client mainly receives data.
WebSockets vs SSE: what are the key differences?
WebSockets support bidirectional communication and are suited for interactive apps; SSE is unidirectional (server-to-client) and simpler for live updates. SSE uses standard HTTP, while WebSockets use the ws/wss protocol.
What are Real-Time Systems in computer science?
Real-time systems require responses within strict time limits, prioritizing low latency and predictable timing. They often use WebSockets or SSE to deliver timely information in applications like gaming, trading, or monitoring.