WebSocket Stream write lock

[chorvus]

My server is crashing on:

this.connection.addListener('data', function(data){
                  ^
TypeError: Cannot call method 'addListener' of null

@transports/websocket.js:101

I traced the error and I found out that this.connection is set to null because of an error in WebSocket.prototype._write:

Error: Stream is not writable
    at Stream._writeOut (net:687:11)
    at Stream.write (net:673:17)
    at [object Object]._write (/usr/local/lib/node/.npm/socket.io/0.6.3/package/lib/socket.io/transports/websocket.js:168:21)
    at [object Object]._payload (/usr/local/lib/node/.npm/socket.io/0.6.3/package/lib/socket.io/client.js:102:28)
    at [object Object]._onConnect (/usr/local/lib/node/.npm/socket.io/0.6.3/package/lib/socket.io/transports/websocket.js:96:8)

My temporary fix to stop the crashes is to add
if ( !this.connection ) return;

just before

this.connection.addListener('data', function(data){

@transports/websocket.js:101

[chorvus]

I investigated further the origin of the error and it seems that the stream is locked by a TCP error:

{ message: 'ECONNABORTED, Software caused connection abort'
, stack: [Getter/Setter]
, errno: 113
, syscall: 'write'
}

I can't provide a minimal c/s testcase at the moment, I will try to compile one soon.

[rauchg]

Sweet, keep me posted. Aren't we try/catching in _write ?

[chorvus]

Aren't we try/catching in _write ?

Yes, but catching an error leads to socket close/client destruction ( this.connection = null ). Then moving back to _onConnect this.connection.addListener( ... it crashes.

Sadly, it seems that I can't provide a testcase at all. Reproducing an ECONNABORT error the exact moment is off my technical knowledge. Although you can emulate the bug simply by inducing an error in _write 's try branch. (it might be present in other transports as well)

[vguzev]

Hello! It looks like that I have the same problem - Socket.IO is crashing with the following messages:
1:
--8<----------------------------------------------------
25 May 01:10:51 - Invalid WebSocket key: "1 9 0GET /socket.io/flashsocket HTTP/1.1". Dropping connection
25 May 01:10:51 - Client 5420995124150068 connected

/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:101
this.connection.addListener('data', function(data){
^
TypeError: Cannot call method 'addListener' of null
at [object Object]._onConnect (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:101:19)
at [object Object]. (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/client.js:23:8)
at [object Object]. (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:9:10)
at new (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/flashsocket.js:8:13)
at [object Object]._onConnection (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/listener.js:165:74)
at [object Object].check (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/listener.js:84:12)
at Server. (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/listener.js:40:15)
at Server.emit (events.js:81:20)
at Socket. (http.js:1024:14)
at Socket._onReadable (net.js:677:27)
--8<-----------------------------------------------------

2:
--8<-----------------------------------------------------
net.js:835
throw new Error('The connection is not writable');
^
Error: The connection is not writable
at Socket._shutdown (net.js:835:11)
at Socket.flush (net.js:519:12)
at Socket.end (net.js:867:14)
at Server. (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/flashsocket.js:38:16)
at Server.emit (events.js:64:17)
at IOWatcher.callback (net.js:944:12)
--8<-----------------------------------------------------

This happens only on production site (with hundreds of online users), so I have no idea how to debug it/fix it... :(

[vguzev]

One more error:
--8<-----------------------------------------------------
/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:127
, k1 = this.request.headers['sec-websocket-key1']
^
TypeError: Cannot read property 'headers' of null
at [object Object]._proveReception (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:127:24)
at Socket. (/home/www/www.mysite.ru/utils/socket.io/lib/socket.io/transports/websocket.js:115:14)
at Socket.emit (events.js:64:17)
at Socket._onReadable (net.js:667:31)
at IOWatcher.onReadable as callback
--8<-----------------------------------------------------

[rauchg]

This has been fixed in 0.7