It sounds like you are running out of ephemeral ports. To check, use the netstat command and look for several thousand ports in the TIME_WAIT state. On Mac OS X the default ephemeral port range is 49152 to 65535, for a total of 16384 ports. You can check this with the sysctl command: $ sysctl … Read more
HTTP is an application protocol. It basically means that HTTP itself can’t be used to transport information to/from a remote end point. Instead it relies on an underlying protocol which in HTTP’s case is TCP. You can read more about OSI layers if you are interested. Sockets on the other hand are an API that … Read more
The Issues First of all you need to be looking at the server port that the server is bound on (app.listen(3001);) on the client side in order to reach the server at all. As for socket.io, adding http://localhost:3001 before the rest of the source in the link tag solves this problem. This is apparently due … Read more
Explanation: This problem occurs because Chrome allows up to 6 open connections by default. So if you’re streaming multiple media files simultaneously from 6 <video> or <audio> tags, the 7th connection (for example, an image) will just hang, until one of the sockets opens up. Usually, an open connection will close after 5 minutes of … Read more
webSockets and regular sockets are not the same thing. A webSocket runs over a regular socket, but runs its own connection scheme, security scheme and framing protocol on top of the regular socket and both endpoints must follow those additional steps for a connection to even be made. You can see the webSocket protocol here: … Read more
With socket.emit you can register custom event like that: server: var io = require(‘socket.io’).listen(80); io.sockets.on(‘connection’, function (socket) { socket.emit(‘news’, { hello: ‘world’ }); socket.on(‘my other event’, function (data) { console.log(data); }); }); client: var socket = io.connect(‘http://localhost’); socket.on(‘news’, function (data) { console.log(data); socket.emit(‘my other event’, { my: ‘data’ }); }); Socket.send does the same, but … Read more
It looks like what you are looking for is an graceful shutdown. First your code does not work because you are closing socket immediately after calling shutdown. The rule is that in a graceful shutdown, both sides must be aware of the shutting down and have acknowledged it before any actually closes the socket. I … Read more
The connection should remain open regardless but yes it’s often common to see protocols implement a heartbeat in order to help detect dead connections, IRC with the PING command for example.
To answer your questions. Even though they achieve (in general) similar things, yes, they are really different. WebSockets typically run from browsers connecting to Application Server over a protocol similar to HTTP that runs over TCP/IP. So they are primarily for Web Applications that require a permanent connection to its server. On the other hand, … Read more