So the Web Socket spec is a little vague on how JS is notified when
the targeted web socket server is down/nonexistent/etc.
Firefox is firing an 'error' event when this happens, based on the language
here in the W3C spec:
"if the status code received from the server is not 101 (e.g. it is a redirect),
the user agent must fail the websocket connection"
Chrome is not calling onerror for this, so we have a difference here. The
language in the spec isn't really clear if this covers the
connection-never-happened case.
Both Chrome and Firefox (haven't tested other browsers/clients) are then
calling close with code=1006, which seems the best code available
in RFC 6455, but the language there isn't great either:
"to indicate that the connection was closed abnormally, e.g., without sending or
receiving a Close control frame."
There's essentially no mention in either spec of what happens when there never
was any connection to the server..
It would be useful to be clear about whether onerror should be called here.
I'm also wondering if it would be useful to have a dedicated
error code for this case ("server not available').
Also: I expect every browser that implements web sockets will have some limit
on the number of websockets it allows to be open at once
(to prevent DoS attacks if nothing else). I'm not sure of what the right
close code for this is. Ideas? Perhaps we could also use a dedicated code for
this case too.
Jason Duell
Mozilla
