The error
When the user opens http://sync.aws.af.cm/, the Google Chrome JavaScript Console shows (within a few seconds):
Unexpected response code: 502 error
The app should remember the contents of the text area even after the user refreshes the page. The app works locally, but not when I upload it to AppFog, and I suspect the problem is the 502 error.
Do you know what might cause this error in this case?
What I've tried
I tried changing the script src=<path_to_socket_io> path in my client from /socket.io/socket.io.js to node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js as described here, but it did not help.
I also tried serving the app at Heroku instead of AppFog, but in that case I kept running into the issue described here even though I specified socket.io version 0.9.6.
I've also looked at the following questions, but the comments so far don't seem to help me.
socket.io creating 502 Bad Gateway on connect / websocket invalid
Socket.IO node.js websocket connection invalid port 8081
socket.io with node.js not working as expected
Relevant server code
Here is the relevant server code:
var server = http.createServer(function (req, res) {
...
});
var io = require('socket.io').listen(server);
// Define events that can be triggered by the client
io.sockets.on('connection', function (socket) {
socket.on('setServerVariable', function (value) {
...
});
...
});
server.listen(process.env.VCAPP_APP_PORT || 3000);
Relevant client code
<script src="/socket.io/socket.io.js"></script>
<script>
window.onload = function () {
...
var socket = io.connect(window.location.hostname);
socket.emit('getServerVariable');
...
};
...
Server log
$ af logs sync
====> /logs/stdout.log <====
info: socket.io started
debug: served static content /socket.io.js
debug: client authorized
info: handshake authorized veNnUVtoDTIz-oudG7Pa
debug: setting request GET /socket.io/1/websocket/veNnUVtoDTIz-oudG7Pa
debug: set heartbeat interval for client veNnUVtoDTIz-oudG7Pa
warn: websocket connection invalid
info: transport end (undefined)
debug: set close timeout for client veNnUVtoDTIz-oudG7Pa
debug: cleared close timeout for client veNnUVtoDTIz-oudG7Pa
debug: cleared heartbeat interval for client veNnUVtoDTIz-oudG7Pa
debug: served static content /socket.io.js
debug: client authorized
info: handshake authorized 6AKyhROUNjqujk_uG7Pb
debug: setting request GET /socket.io/1/websocket/6AKyhROUNjqujk_uG7Pb
debug: set heartbeat interval for client 6AKyhROUNjqujk_uG7Pb
warn: websocket connection invalid
info: transport end (undefined)
debug: set close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: cleared close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: cleared heartbeat interval for client 6AKyhROUNjqujk_uG7Pb
debug: setting request GET /socket.io/1/xhr-polling/6AKyhROUNjqujk_uG7Pb?t=1348504130465
debug: setting poll timeout
debug: client authorized for
debug: clearing poll timeout
debug: xhr-polling writing 1::
debug: set close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: setting request GET /socket.io/1/xhr-polling/6AKyhROUNjqujk_uG7Pb?t=1348504130724
debug: setting poll timeout
debug: discarding transport
debug: cleared close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: xhr-polling received data packet 5:::{"name":"getServerVariable"}
debug: clearing poll timeout
debug: xhr-polling writing 5:::{"name":"printLog"}
debug: set close timeout for client 6AKyhROUNjqujk_uG7Pb
server.js: getServerVariable:
debug: setting request GET /socket.io/1/xhr-polling/6AKyhROUNjqujk_uG7Pb?t=1348504130980
debug: setting poll timeout
debug: clearing poll timeout
debug: xhr-polling writing ���23���5:::{"name":"printLog"}���39���5:::{"name":"setItemValue","args":[""]}���23���5:::{"name":"printLog"}
debug: set close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: discarding transport
debug: cleared close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: setting request GET /socket.io/1/xhr-polling/6AKyhROUNjqujk_uG7Pb?t=1348504131261
debug: setting poll timeout
debug: discarding transport
debug: cleared close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: clearing poll timeout
debug: xhr-polling writing 8::
debug: set close timeout for client 6AKyhROUNjqujk_uG7Pb
debug: xhr-polling closed due to exceeded duration
debug: setting request GET /socket.io/1/xhr-polling/6AKyhROUNjqujk_uG7Pb?t=1348504151659
debug: setting poll timeout
debug: discarding transport
debug: cleared close timeout for client 6AKyhROUNjqujk_uG7Pb
