Senior LevelNode JS
How do you scale 1,000,000 concurrent WebSocket connections across multiple Node.js servers using Redis Pub/Sub?
❓ Interview Prompt: Explain scaling WebSockets horizontally, SSL termination at load balancer, IP hash sticky sessions, and Redis Pub/Sub message routing.
Scaling 1,000,000 concurrent WebSockets requires distributing connections across multiple Node.js server nodes:
Architecture:
1
Load Balancer: IP Hash sticky sessions for initial handshake.
2
Redis Pub/Sub: Server A receives a message for a user connected to Server B; Server A publishes to Redis Pub/Sub, and Server B delivers to the local WebSocket connection!
Code Implementation Example
javascript
console.log('Redis Pub/Sub routes WebSocket messages across distributed Node.js nodes');💡Scaling WebSockets horizontally with Redis Pub/Sub.
🎯 Interview Key Takeaway
Use Redis Pub/Sub to route WebSocket events across horizontally scaled Node.js server nodes.
#WebSockets#Redis Pub/Sub#Horizontal Scaling#Senior
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