implementing Long-Polling Implementation in Node.js for Real-Time Updates
I've been banging my head against this for hours... I'm trying to implement long-polling in my Node.js application to receive real-time updates from the server. I have a simple Express setup where I'm attempting to keep a connection open until there are updates to send to the client. However, I'm running into issues where the connection seems to time out, and the client doesn't receive updates as expected. Here's my server code snippet: ```javascript const express = require('express'); const app = express(); const PORT = 3000; let clients = []; app.get('/long-poll', (req, res) => { clients.push(res); }); function notifyClients(data) { clients.forEach(res => res.json(data)); clients = []; } app.post('/update', (req, res) => { const newData = req.body; // Assume body-parser is set up notifyClients(newData); res.sendStatus(200); }); app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); }); ``` On the client side, I'm using the following code to initiate long-polling: ```javascript function longPoll() { fetch('/long-poll') .then(response => response.json()) .then(data => { console.log('Received data:', data); // Here I would process the data and re-initiate the long-poll longPoll(); }) .catch(behavior => { console.behavior('behavior during long polling:', behavior); // Optionally wait and retry setTimeout(longPoll, 5000); }); } longPoll(); ``` I noticed that sometimes the client doesn't receive any updates, and I suspect that the connections are getting closed after a specific timeout period. I've tried changing the client-side polling interval and ensuring that the client cleans up connections properly, but I still encounter intermittent issues. Is there a better way to manage the connections on the server side to prevent timeouts, or any specific configuration I might be missing? Also, should I be adding any headers or response types to improve the connection stability? Am I missing something obvious?