使用带有AppFog的socket.io时出现意外的响应代码:502错误

Question

错误

当用户打开http://sync.aws.af.cm/时,Google Chrome JavaScript控制台会显示(几秒钟内):

Unexpected response code: 502 error

即使用户刷新页面,应用程序也应该记住文本区域的内容.该应用程序在本地工作,但不是当我上传到AppFog时,我怀疑问题是502错误.

你知道在这种情况下会导致这个错误的原因吗？

我试过的

我试图改变script src=<path_to_socket_io>从我的客户端的路径/socket.io/socket.io.js来node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js描述这里,但它并没有帮助.

我也尝试在Heroku而不是AppFog上提供应用程序,但在这种情况下,即使我指定了socket.io版本0.9.6 ,我仍然遇到此处描述的问题.

我也看过以下问题,但到目前为止的评论似乎对我没有帮助.

socket.io在connect/websocket上创建502 Bad Gateway无效

Socket.IO node.js websocket连接无效端口8081

socket.io与node.js无法按预期工作

相关的服务器代码

这是相关的服务器代码:

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);

相关的客户代码

<script src="/socket.io/socket.io.js"></script>

<script>
  window.onload = function () {
    ...
    var socket = io.connect(window.location.hostname);
    socket.emit('getServerVariable');
    ...
  };
...

服务器日志

$ 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

Answer 1

AppFog尚不支持websockets.在他们最近收购Nodester之后,他们宣布将在几个月内收购.

通过添加io.set('transports', ['xhr-polling']);你只是将传输设置为ajax长轮询.默认情况下,Socket.io根据浏览器功能和当前连接确定最佳传输.Websockets是理想的,当它可用时,但如果它不是Socket.io将回退到其他传输中的xhr-polling.

我502 unexpected response / bad gateway在使用CloudFlare时也收到了同样的错误,CloudFlare也无法通过基于nginx的基础架构代理websocket连接(请注意,截至2014年,如果您使用的是高级计划,Cloudflare可以代理websockets).