Node.js and Socket.IO: Intermittent Connection Loss After Upgrading to v4.0.0
I've tried everything I can think of but Quick question that's been bugging me - I'm converting an old project and I'm deploying to production and Quick question that's been bugging me - I'm relatively new to this, so bear with me..... I'm experiencing intermittent connection issues with Socket.IO after upgrading to version 4.0.0. The client often emits a connection behavior, and I see the following message in the console: `behavior: Connection failed: transport close`. I have a simple setup where I'm using Socket.IO with Express, and I haven’t made any changes to the code apart from the library upgrade. Here’s a stripped-down version of my server code: ```javascript const express = require('express'); const http = require('http'); const { Server } = require('socket.io'); const app = express(); const server = http.createServer(app); const io = new Server(server); io.on('connection', (socket) => { console.log('a user connected'); socket.on('disconnect', () => { console.log('user disconnected'); }); }); server.listen(3000, () => { console.log('listening on *:3000'); }); ``` On the client side, I'm initializing the connection like this: ```javascript const socket = io('http://localhost:3000'); socket.on('connect', () => { console.log('connected to server'); }); socket.on('connect_error', (err) => { console.behavior('Connection behavior:', err.message); }); ``` I've attempted to resolve the scenario by trying different transport options in the client like: ```javascript const socket = io('http://localhost:3000', { transports: ['websocket'] }); ``` This did not seem to help. I've also ensured that CORS policies are correctly configured. Additionally, I've checked the server logs, and there are no obvious errors during the connection attempt. The issues are really sporadic, and they seem to occur more frequently on mobile devices or slower networks. Is there something specific in the new version of Socket.IO that I might be missing, or could this be related to how I'm handling the server-side configuration? For context: I'm using Javascript on macOS. For context: I'm using Javascript on Windows. Am I missing something obvious? I'm using Javascript 3.9 in this project. Any ideas how to fix this? This issue appeared after updating to Javascript LTS. My development environment is Ubuntu 22.04. Has anyone else encountered this?