CODEWITHSUNDEEP
node.jssocket.io
Microsis
Microsis

Reputation: 279

Socket IO server restart causes duplicate client emits

When I make changes to my Node/Socket IO server and restart it, the connected client will start emitting two messages for each one. If I restart again, it will start emitting three, and so forth.

The only "fix" I see is to refresh the page on client to force a new connection.

How do I prevent the client from emitting multiple messages after a server restart?

Pretty standard setup:

Server

const app = express();
const port = process.env.PORT || 4000;
const server = app.listen(port, () => l(`Server started on port ${port}`));
const io = require('socket.io').listen(server);

app.get('/', (req, res) => {
   res.sendFile('/public/index.html', { root: __dirname });
});

io.on('connection', client => client.on('event', (msg) => console.log(msg));

Client

const socket = io.connect('', { query: { path: window.location.pathname }, reconnect: false, forceNew: true });

$("body").on("click", "a", () => socket.emit('event', 'test'));

Upvotes: 0

Views: 1322

Answers (1)

nosTa
nosTa

Reputation: 653

Here is the solution: https://github.com/socketio/socket.io/issues/430#issuecomment-451130988

Don't wrap the socket.on in actions like connect or authenticated.

In my example I had a "socket.on" wrapped in authorization. As soon as the client reconnected the socket.on stacked up and multiplied each time the server restarted.

Upvotes: 2

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