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   <H1>[99s-extend] timeout in cowboy loop handler</H1>
    <B>Lo&#239;c Hoguin</B> 
    <A HREF="mailto:extend%40lists.ninenines.eu?Subject=Re%3A%20%5B99s-extend%5D%20timeout%20in%20cowboy%20loop%20handler&In-Reply-To=%3C525E179F.2010200%40ninenines.eu%3E"
       TITLE="[99s-extend] timeout in cowboy loop handler">essen at ninenines.eu
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    <I>Wed Oct 16 06:35:43 CEST 2013</I>
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<PRE>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:
&gt;<i> thanks. one more question if you do not mind. you say that we need
</I>&gt;<i> timeouts when the client does not notify us when it dies. but then you
</I>&gt;<i> say that if the client dies then the socket write will fail. to me this
</I>&gt;<i> sounds like a contradiction. would you please clarify?
</I>&gt;<i>
</I>&gt;<i> (I assume that this is the problem that we are discussing:
</I>&gt;<i> <A HREF="http://stackoverflow.com/questions/283375/detecting-tcp-client-disconnect,">http://stackoverflow.com/questions/283375/detecting-tcp-client-disconnect,</A>
</I>&gt;<i> right?)
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i> 2013/10/16 Lo&#239;c Hoguin &lt;<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A> &lt;mailto:<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A>&gt;&gt;
</I>&gt;<i>
</I>&gt;<i>     On 10/16/2013 05:48 AM, akonsu wrote:
</I>&gt;<i>
</I>&gt;<i>         1. do you mean that there is no way on the server side to tell
</I>&gt;<i>         if the
</I>&gt;<i>         client has disconnected?
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>     There are ways, and Cowboy will happily detect them. There's also
</I>&gt;<i>     the problem that a side may be closed without the other side knowing
</I>&gt;<i>     about it, which is why you need timeouts.
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>         2. if I use a normal handler, I will still run into the same
</I>&gt;<i>         problem, it
</I>&gt;<i>         does not matter which handler I use, from the standpoint of deciding
</I>&gt;<i>         whether the client is still there, right?
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>     If the client is gone, the send will fail. Normal handlers are
</I>&gt;<i>     pretty much the same except they don't have a timeout, because your
</I>&gt;<i>     code has an explicit end.
</I>&gt;<i>
</I>&gt;<i>         I am confused as to how I can implement my streaming and not
</I>&gt;<i>         drop the
</I>&gt;<i>         connection on each client and yet make sure I do close the
</I>&gt;<i>         connections
</I>&gt;<i>         when the clients disconnect...
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>         2013/10/15 Lo&#239;c Hoguin &lt;<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A>
</I>&gt;<i>         &lt;mailto:<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A>&gt; &lt;mailto:<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A>
</I>&gt;<i>         &lt;mailto:<A HREF="https://lists.ninenines.eu/listinfo/extend">essen at ninenines.eu</A>&gt;&gt;&gt;
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>              Infinite is bad practice, yes. Infinite means some
</I>&gt;<i>         connections will
</I>&gt;<i>              *never* be closed, eating FDs and memory for nothing.
</I>&gt;<i>
</I>&gt;<i>              I'm not sure why you want to receive messages, you could
</I>&gt;<i>         just use a
</I>&gt;<i>              normal handler that asks for more data, sends it, ask for
</I>&gt;<i>         more data,
</I>&gt;<i>              sends it, etc.
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>
</I>&gt;<i>     --
</I>&gt;<i>     Lo&#239;c Hoguin
</I>&gt;<i>     Erlang Cowboy
</I>&gt;<i>     Nine Nines
</I>&gt;<i>     <A HREF="http://ninenines.eu">http://ninenines.eu</A>
</I>&gt;<i>
</I>&gt;<i>
</I>

-- 
Lo&#239;c Hoguin
Erlang Cowboy
Nine Nines
<A HREF="http://ninenines.eu">http://ninenines.eu</A>

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