node.js - 使用 AppFog 的意外响应代码 : 502 error when using socket. io

Question

错误

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

Unexpected response code: 502 error

即使在用户刷新页面后，应用程序也应该记住文本区域的内容。该应用程序在本地运行，但当我将其上传到 AppFog 时无法运行，我怀疑问题是 502 错误。

您知道在这种情况下可能导致此错误的原因是什么吗？

我尝试过的

我尝试更改 script src=<path_to_socket_io>我的客户端中的路径来自 /socket.io/socket.io.js至node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js如所述here ，但没有帮助。

我还尝试在 Heroku 而不是 AppFog 上提供应用程序，但在这种情况下，我一直遇到所描述的问题 here即使我指定了 socket.io 版本 0.9.6。

我还查看了以下问题，但到目前为止的评论似乎对我没有帮助。

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

相关服务器代码

这里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);

相关客户端代码

<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 还不支持 websocket。在最近收购 Nodester 之后，他们宣布将在几个月后推出。

通过添加 io.set('transports', ['xhr-polling']); 您只是将传输设置为 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方式。 Websockets 是理想的，当它可用时，但如果它不是，Socket.io 将在其他传输中回退到 xhr-polling。

我在使用 CloudFlare 时收到了同样的 502 unexpected response/bad gateway 错误，该错误也无法通过其基于 nginx 的基础设施代理 websocket 连接(请注意，截至 2014 年，Cloudflare 可以代理 websockets如果您使用的是高级计划)。