[mythtv] What happens with connections when a client dies?

[gettler at acm.org]

No, you do not need to be constantly reopening the connection.  The only
time mvpmc will close its connection is if it detects that the backend
has gone away.

I assume mythfrontend is the same way, since it hangs every time I restart
mythbackend.

Jon

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> Only just got around to digesting some of the stuff being said here;
> its been a long couple of days!
> 
> So, if a socket could stay open unoticed, do they just keep piling up?
>  Does it cause a system slow down, laggy network traffic, a huge
> memory overhead or simply sit there doing nothing negative.
> 
> The reason I ask, I notice MythWeb opens and closes the connection
> everytime it queries the backend.  With the Java stuff I am doing I
> was wandering whether I could really on my Java backend just
> maintaining the connection open for the whole time the Java process is
> running, or should the backend open and close the connection each
> time?
> 
> Dave
> 
> 
> On Thu, 24 Feb 2005 17:44:05 +0100, Holger Buchfink
> <avalanche at beyondmonkey.com> wrote:
> > David Whyte wrote:
> > > I have noticed that the proper way to close the socket is to call the
> > > DONE command over the MythProtocol, but I was wandering what effects
> > > this would have if it weren't done *everytime* (such as when the
> > > frontend dies in a nasty way).  Do the open connections get 'garbage
> > > collected' after a certain period of time?
> > 
> > Depends. There really is no short answer. There's TCP, your client's
> > kernel (sockets), Qt and Myth. The outcome is dependent on what goes
> > wrong and when.
> > 
> > If the client (Myth) dies and it's kernel doesn't, the kernel will
> > close the socket and all is well.
> > 
> > If the kernel dies, (or you pull the network cable on the client)
> > and there is something on the wire, in this case TCP is moving
> > something, TCP should timeout and close the connection.
> > 
> > Same as above, the kernel dies etc, but nothing is on the wire and
> > the server or client don't try to send anything. In this case,
> > the socket can stay open unnoticed.
> > 
> > Sockets do provide a keep-alive that lets TCP periodically, default
> > is 2 hours check the connection, if nothing happens. Qt doesn't implement
> > this option, probably since it's platform dependent and not reliable.
> > Myth backend does not currently check the connections, either. Some of
> > it's connections only send stuff on client request, so I think it is
> > currently possible that a socket can stay open unnoticed.
> > 
> > Holger
> > _______________________________________________
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> > 
> 
> 
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