Node.js and Socket.IO - Intermittent Disconnection Issues on High Load
I've searched everywhere and can't find a clear answer. I'm experiencing intermittent disconnection issues with Socket.IO in my Node.js application, particularly under high load. I'm using Socket.IO v4.0.0 with a Node.js server running on Express. The server handles real-time messaging and seems to work fine with a small number of connected clients, but when I scale up to about 100 simultaneous connections, I notice some clients getting disconnected frequently with the behavior message: `transport behavior`. I've already tried increasing the `pingInterval` and `pingTimeout` settings, but it hasn't resolved the question. Here's the relevant part of my server setup: ```javascript const express = require('express'); const http = require('http'); const socketIo = require('socket.io'); const app = express(); const server = http.createServer(app); const io = socketIo(server, { pingInterval: 10000, // 10 seconds pingTimeout: 5000, // 5 seconds }); io.on('connection', (socket) => { console.log('New client connected:', socket.id); socket.on('disconnect', (reason) => { console.log('Client disconnected:', socket.id, 'Reason:', reason); }); }); server.listen(3000, () => { console.log('Server listening on port 3000'); }); ``` I've also monitored the server's CPU and memory usage, and they seem reasonable during peak loads. Additionally, I'm behind a reverse proxy (Nginx) configured to handle WebSocket connections, and I've ensured that the configuration is set up correctly. Here's part of my Nginx config for the WebSocket handling: ```nginx location /socket.io/ { proxy_pass http://localhost:3000; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; } ``` Despite these settings, clients still face disconnection issues. Is there something I'm missing in my implementation or configuration? Any suggestions would be greatly appreciated. I'm working on a REST API that needs to handle this. Any ideas what could be causing this?