ZScaler/Proxy issue and/or SocketIO bug?

[cadguy]

Our SocketIO expert noticed the following. Have other's seen this too?

(1) The client is handshaking with the server with a standard xhr
exchange just fine. In this step, the server hands the client some
sort of session id and a couple of tidbits along with a a list of
transports supported by the server. e.g. "websockets,htmlfile,xhr-
polling,json-polling"

(2) The client attempts to establish a websockets connection to the
server. It gets as far as creating the socket and setting the
handlers for onOpen, onMessage, onError, onClose, and it recieves the
onOpen event. I can see the websockets upgrade request in the chrome
debugger and it has a response.

(3) Then it just sits and waits [a configurable] 10 seconds until the
connect timeout fires. There is supposed to be a message from the
server indicating that the connection is active, but this never
happens on the client.

(4) The job of the connect time out is to try the remaining
transports... this it does, but the client keeps getting errors from
the server that there has been no handshake. This matches many log
messages I am seeing on the server. I haven't yet been able to dig in
to the issue more.

Thanks!
Shrirang

[Ron Adams]

Are you using wss://?  If not, you're going to have a ton of issues with ZScaler.  We had the exact same problems and our contacts at ZScaler were of no help to us.  Eventually we took a stab at using wss:// instead of ws:// after seeing that other socket.io sites were not having the same issues behind the same ZScaler.........once we switched we had no more issues.