Error: This socket is closed.

[nicokaiser]

I just got this crash:

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: This socket is closed.
    at Socket._write (net.js:474:19)
    at Socket.write (net.js:466:15)
    at WebSocketServer.<anonymous> (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:292:16)
    at /home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:321:25
    at WebSocketServer.handleHixieUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:368:3)
    at WebSocketServer.handleUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:141:61)
    at Server.handleUpgrade (/home/wwwdocs/applications/services/webpush/lib/engine/lib/server.js:70:11)
    at Server.<anonymous> (/home/wwwdocs/applications/services/webpush/lib/engine/lib/webpush-engine.js:47:12)
    at Server.emit (events.js:88:20)
    at Socket.<anonymous> (http.js:1483:14)

node.js 0.6.17, ws 0.4.15.

I think (!) this has nothing to do with the latest update of WebSocketServer.js – and I wonder why this error was not caught by the try/catch (maybe this is a deferred thing again, and you have to check if the socket is open before the writes).

[nicokaiser]

Just upgraded to node.js 0.6.18, but I'm not too optimistic...

I really don't understand when socket.write throws an exception and when it emits an 'error' event. You are try/catching exceptions, so either the write must be delayed, or emitting an error event which is not caught by the default http error handler (https://github.com/joyent/node/blob/master/lib/http.js#L1311) for some reason.

Maybe a check if the socket is still writable in completeHandshake workarounds this, but I'd like to understand it first...

Let's see if node 0.6.18 fixes or at least spits out a better backtrace.

[nicokaiser]

Update: it crashed again:

events.js:48
        throw arguments[1]; // Unhandled 'error' event
                       ^
Error: This socket is closed.
    at Socket._write (net.js:474:19)
    at Socket.write (net.js:466:15)
    at WebSocketServer.<anonymous> (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:292:16)
    at /home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:321:25
    at WebSocketServer.handleHixieUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:368:3)
    at WebSocketServer.handleUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:141:61)
    at Server.handleUpgrade (/home/wwwdocs/applications/services/webpush/lib/engine/lib/server.js:79:11)
    at Server.<anonymous> (/home/wwwdocs/applications/services/webpush/lib/engine/lib/webpush-engine.js:47:12)
    at Server.emit (events.js:88:20)
    at Socket.<anonymous> (http.js:1521:14)

Now trying to add error and timeout handlers to the socket before handleUpgrade.

[nicokaiser]

So far no crashes, but I'll observe it over the day.

These handlers should be in ws as the server should not crash before I (the application) have the chance to react and catch those crashes...

[nicokaiser]

Update: still crashes even if I catch the socket's error event. This is really bad.

events.js:48
        throw arguments[1]; // Unhandled 'error' event
        ^
Error: This socket is closed.
    at Socket._write (net.js:474:19)
    at Socket.write (net.js:466:15)
    at WebSocketServer.<anonymous> (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:292:16)
    at /home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:321:25
    at WebSocketServer.handleHixieUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:368:3)
    at WebSocketServer.handleUpgrade (/home/wwwdocs/applications/services/webpush/node_modules/ws/lib/WebSocketServer.js:141:61)
    at Server.handleUpgrade (/home/wwwdocs/applications/services/webpush/lib/engine/lib/server.js:79:11)
    at Server.<anonymous> (/home/wwwdocs/applications/services/webpush/lib/engine/lib/webpush-engine.js:47:12)
    at Server.emit (events.js:88:20)
    at Socket.<anonymous> (http.js:1521:14)

[nicokaiser]

I have no idea

• where this happens
• why there is not 'error' handler (as I'm defining one before handing the socket to handleUpgrade)

Now I added a check for socket.writable before writing the nonce, let's wait some hours to see if this fixes the problem. Sigh.

[einaros]

Does #75 work for you? I have a different fix brewing, which seems to be a more long-term way to handle this issue. That'll take me a couple of hours to implement, though.

[nicokaiser]

@einaros: so far it seems so...

How would you like to handle it other that that? Seems like node's socket.write is quite a mess, as it can a) throw exceptions b) return false and c) emit an 'error' if something goes wrong...

[einaros]

Closing this - let's reiterate if the current fixes aren't sufficient :)