Bdtjtk

I created socket io server using nodejs and from android connected to the server.

I am using io. socket: socket. io-client: 1.0.0 library for android.

The problem was when I try to send message when open app it works. But when I reconnect socket I it not works. Just when second reconnection it works. Every second connection. Previously I tried to add users to client variable, then emit to socketid. But now I am using the rooms.

I think socket io server store old room, and for second connection it works properly

How can I refresh rooms before broadcast or broadcast last updated rooms?

server.js

module.exports = (httpsServer) => {

    const io = require('socket.io')(httpsServer, {

        log: false,

        cookie: false,

        multiplex: false

    });

    io.set({

        transports: ['websocket', 'polling']

    });

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



        ocket.on('join', (id) => {

            console.log(id + " joined");

            socket.join(id);

        });

        socket.on('disconnect', (id) => {

            console.log(id + " leaved");

            socket.leave(id);

        });



        socket.on('messageToUser', (endUserId, msg) => {

            console.log("admin broadcast to: " + endUserId);

            socket.broadcast.to(endUserId).emit('inbox', {

                senderId: '1',

                endUser: endUserId,

                message: msg

            });

            socket.emit('inbox', {

                senderId: '1',

                endUser: endUserId,

                message: msg

            });

        });

    });

};

App.java

public class App extends Application {



    private Socket mSocket;

    {

        try {

            IO.Options opts = new IO.Options();

            opts.secure = true;

            opts.transports = new String{WebSocket.NAME};

            opts.reconnection = true;

            opts.forceNew = true;

            opts.multiplex = false;

            mSocket = IO.socket("...",opts);

        } catch (URISyntaxException e) {

            throw new RuntimeException(e);

        }

    }



    public Socket getSocket() {

        return mSocket;

    }

}

ChatActivity.java

    App app = (App) getApplication();

        mSocket = app.getSocket();

        mSocket.on(Socket.EVENT_CONNECT,onConnect);

        mSocket.on(Socket.EVENT_DISCONNECT,onDisconnect);

        mSocket.on(Socket.EVENT_CONNECT_ERROR, onConnectError);

        mSocket.on("inbox", inbox);

        mSocket.connect();

sendButton.setOnClickListener(v -> {

            if (!mSocket.connected()) return;

            if(!messageEditText.getText().toString().trim().isEmpty()){

                mSocket.emit("messageToUser", endUserId, messageEditText.getText().toString()); 

                messageEditText.setText("");

            }

        });



private Emitter.Listener onConnect = new Emitter.Listener() {

        @Override

        public void call(Object... args) {

            runOnUiThread(new Runnable() {

                @Override

                public void run() {

                    if(!isConnected) {

                        mSocket.emit("join", userInfoSharedP.getUserId()); 

 isConnected = true;

                    }

                }

            });

        }

    };



...

you need background or foreground service for ChatActivity or at least asynctask , also u can use global public variable for socket instance this is needed for properly running

I found a problem. I am using pm2 process manager. And I run PM2 with its built in load balancer. Something like this:

pm2 start server -i 2

And when I stop pm2 and start own node server, it works properly. I think problem in load balancing with 2 core. And when I connect socket every second connection emit works. It is because of dividing processes into two.

Firstly install redis

# on mac

brew install redis

sudo brew services start redis

Then install the socket.io redis adapter in project

npm i socket.io-redis --save

Finally,

const sockets = require('socket.io')

const redis = require('socket.io-redis')



const bindListeners = (io) => {

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

    console.log(`${socket.id} connected`)

  })

}



module.exports = (server) => {

  const io = sockets(server, {

    transports: [ 'websocket', 'polling' ]

  })

  // Add the redis adapter

  io.adapter(redis({ host: 'localhost', port: 6379 }))   

  bindListeners(io)

}