[99s-extend] timeout in cowboy loop handler

[Loïc Hoguin]

Loop handlers are designed to wait for a long time with the socket 
*idle* and then eventually send one response then close the socket. 
Things like long-polling.

What you are doing is just streaming, for which you do not need a 
timeout because the socket isn't idle. You are just sending a large 
response, and normal handlers are perfectly capable of doing that.

On 10/16/2013 06:12 AM, akonsu wrote:
> thanks. one more question if you do not mind. you say that we need
> timeouts when the client does not notify us when it dies. but then you
> say that if the client dies then the socket write will fail. to me this
> sounds like a contradiction. would you please clarify?
>
> (I assume that this is the problem that we are discussing:
> http://stackoverflow.com/questions/283375/detecting-tcp-client-disconnect,
> right?)
>
>
> 2013/10/16 Loïc Hoguin <essen at ninenines.eu <mailto:essen at ninenines.eu>>
>
>     On 10/16/2013 05:48 AM, akonsu wrote:
>
>         1. do you mean that there is no way on the server side to tell
>         if the
>         client has disconnected?
>
>
>     There are ways, and Cowboy will happily detect them. There's also
>     the problem that a side may be closed without the other side knowing
>     about it, which is why you need timeouts.
>
>
>         2. if I use a normal handler, I will still run into the same
>         problem, it
>         does not matter which handler I use, from the standpoint of deciding
>         whether the client is still there, right?
>
>
>     If the client is gone, the send will fail. Normal handlers are
>     pretty much the same except they don't have a timeout, because your
>     code has an explicit end.
>
>         I am confused as to how I can implement my streaming and not
>         drop the
>         connection on each client and yet make sure I do close the
>         connections
>         when the clients disconnect...
>
>
>         2013/10/15 Loïc Hoguin <essen at ninenines.eu
>         <mailto:essen at ninenines.eu> <mailto:essen at ninenines.eu
>         <mailto:essen at ninenines.eu>>>
>
>
>              Infinite is bad practice, yes. Infinite means some
>         connections will
>              *never* be closed, eating FDs and memory for nothing.
>
>              I'm not sure why you want to receive messages, you could
>         just use a
>              normal handler that asks for more data, sends it, ask for
>         more data,
>              sends it, etc.
>
>
>
>     --
>     Loïc Hoguin
>     Erlang Cowboy
>     Nine Nines
>     http://ninenines.eu
>
>


-- 
Loïc Hoguin
Erlang Cowboy
Nine Nines
http://ninenines.eu