using @socket.io/redis-adapter with pm2 in cluster mode on ec2 instance

Question

I am trying to run my node.js application that uses socket.io on a linux ec2 instance using pm2 in cluster mode, when I run my application using pm2 start /var/www/html/backend/index.js I am successfully able to create a connection with my server using socket.io-client library

const socket = io("http://myPublicIp:3001");

but when I try to run my server with pm2 start /var/www/html/backend/index.js -i max I can no longer create a connection with my server.

after some research, I found out that I have to use @socket.io/redis-adapter library in my code but after 3 days of trying, I can't seem to get it to work.

any help would be appretiated

I have installed @socket.io/redis-adapter library and created the adapters. i have also registered the redis adapters to the io object as it was shown in the documentation here

here is my code from index.js

// importing Express server
const express = require("express");
const cors = require('cors');
// initializing our server
const app = express();
const {logger} = require("./config/pino.config");
const socket = require('socket.io');
const http = require('http');
const { createClient } = require("redis");
const { createAdapter } = require("@socket.io/redis-adapter");

// ...
// attaching routers and other modules to my express app
// ...


// listening on PORT or 3001          
const PORT = process.env.SERVER_PORT || 3001;
// const server = app.listen(PORT, () => logger.info(`Listening on port ${PORT}`));
const server = http.createServer(app);

// socket.io
const io = socket(server, {
  cors: {
    origin: '*',
  }
});

// const pubClient = createClient({ host: "localhost", port: 6379 });
const pubClient = createClient({url: 'redis://localhost:6379'});
const subClient = pubClient.duplicate();
// Promise.all([pubClient.connect(), subClient.connect()]).then(() => {
//   io.adapter(createAdapter(pubClient, subClient));
// });

try {
  Promise.all([pubClient.connect(), subClient.connect()]).then(() => {
    io.adapter(createAdapter(pubClient, subClient));
  });
} catch (err) {
  console.error(err);
}

server.listen(PORT, () => logger.info(`Listening on port ${PORT}`));

io.on('connection', (socket, io) => {
  connection(socket, io);
});

gameEvents.on('game_started', (game_id) => {
  handleGameStartedEvent(game_id, io);
});

I don't get any errors when I run my app.

I have installed pm2 on my local machine (windows 11) and when I run pm2 start /var/www/html/backend/index.js -i max it works fine.

also when I run that code using node index.js or pm2 start /var/www/html/backend/index.js it also works fine.

the problem is only when i attach -i max option to the pm2 command.

using @socket.io/redis-adapter with pm2 in cluster mode on ec2 instance

0 Answers0