I am learning on how to use websockets. I am returning data to the front-end from the server via normal ws.send but I would at the same time I would like to have a set interval time to ping the front-end to see if clints are still alive there.. This is the code I am using at the moment.
ws.on('connection', function connection(ws, req) {
ws.on('message', function ining(message) {
return_data = message;
heart_beat = {status:"Accepted", currentTime:"2013-02-01T20:53:32.486Z", "heartbeatInterval":300}
ws.send(JSON.stringify(heart_beat));
const interval = setInterval(function ping() {
ws.clients.forEach(function each(ws) {
if (ws.isAlive === false) return ws.terminate();
ws.isAlive = false;
ws.ping('', false, true);
});
}, 300);
});
});
I want to just wait 300 seconds, if there is no response from the front-end I will terminate the websocket after the first heartbeat send by me
Here is my front-end code.
ws.onopen = function(){
console.log("Connected");
}
ws.onclose = function(){
console.log("Disconnected");
ws.send('Disconnected');
}
Whats happening now is that, when I close the browser in the front-end the server in the back-end is still pinging, if I console.log it.
I am learning on how to use websockets. I am returning data to the front-end from the server via normal ws.send but I would at the same time I would like to have a set interval time to ping the front-end to see if clints are still alive there.. This is the code I am using at the moment.
ws.on('connection', function connection(ws, req) {
ws.on('message', function ining(message) {
return_data = message;
heart_beat = {status:"Accepted", currentTime:"2013-02-01T20:53:32.486Z", "heartbeatInterval":300}
ws.send(JSON.stringify(heart_beat));
const interval = setInterval(function ping() {
ws.clients.forEach(function each(ws) {
if (ws.isAlive === false) return ws.terminate();
ws.isAlive = false;
ws.ping('', false, true);
});
}, 300);
});
});
I want to just wait 300 seconds, if there is no response from the front-end I will terminate the websocket after the first heartbeat send by me
Here is my front-end code.
ws.onopen = function(){
console.log("Connected");
}
ws.onclose = function(){
console.log("Disconnected");
ws.send('Disconnected');
}
Whats happening now is that, when I close the browser in the front-end the server in the back-end is still pinging, if I console.log it.
Share Improve this question asked Oct 15, 2017 at 13:23 Masnad NihitMasnad Nihit 1,9962 gold badges22 silver badges41 bronze badges 15-
What do you mean by
client are still alive? – user2652134 Commented Oct 15, 2017 at 13:28 - @BrahmaDev Client ( in the browser ) - if they close the browser they are gone, thats what I meant. – Masnad Nihit Commented Oct 15, 2017 at 13:30
-
If they close the browser, the websocket connection is gone too. You should no longer find them in
ws.clients. – user2652134 Commented Oct 15, 2017 at 13:37 - @BrahmaDev Not always, I want to use ping messages as a means to verify that the remote endpoint is still responsive. Even in the websocket repo in github they said it and I copied this example from there as well – Masnad Nihit Commented Oct 15, 2017 at 13:39
- Can you please point me to that. This is new to me. – user2652134 Commented Oct 15, 2017 at 13:41
1 Answer
Reset to default 3You have to clear the Timeout with clearInterval
Here is a working example with uWebSocket :
'use strict';
const uws = require('uws');
const PORT = 3000
/*********************************************************************
* Server *
*********************************************************************/
var wsServer = new uws.Server({ 'port': PORT });
let nextId=1;
wsServer.on('connection', function(ws) {
console.log('connection !');
ws.id='cnx'+nextId++;
ws.on('message', function(mess){console.log('message : '+mess); });
ws.on('error', function(error) {
console.log('Cannot start server');
});
ws.on('close', function(code, message) {
console.log('Disconnection: ' + code + ', ' + message);
clearInterval(ws.timer);
});
ws.on('pong',function(mess) { console.log(ws.id+' receive a pong : '+mess); });
ws.timer=setInterval(function(){pingpong(ws);},1000);
});
function pingpong(ws) {
console.log(ws.id+' send a ping');
ws.ping('coucou',{},true);
} // end of pingpong
/*********************************************************************
* Client *
*********************************************************************/
var wsClient1 = createClient('client1');
var wsClient2 = createClient('client2');
function createClient(id) {
var client = new uws('ws://localhost:'+PORT);
client.id=id;
client.on('ping',function(mess){ console.log(this.id+' receive a ping : '+mess); } );
client.on('message',function(mess){ console.log(this.id+' receive a message : '+mess); } );
client.on('close',function(){ console.log(this.id+' closed'); } );
return client;
}
function closeClient(client) {
console.log('close '+client.id); client.close();
}
setTimeout(function(){ closeClient(wsClient1); closeClient(wsClient2); wsServer.close(); },2500);
output is :
connection !
connection !
cnx1 send a ping
cnx2 send a ping
client2 receive a ping : coucou
client1 receive a ping : coucou
cnx1 receive a pong : coucou
cnx2 receive a pong : coucou
cnx1 send a ping
cnx2 send a ping
client2 receive a ping : coucou
client1 receive a ping : coucou
cnx1 receive a pong : coucou
cnx2 receive a pong : coucou
close client1
close client2
client1 closed
client2 closed
Disconnection: 0,
Disconnection: 0,