[e2e] tcp connection timeout

Vadim Antonov avg at kotovnik.com
Thu Mar 2 00:32:39 PST 2006

On Wed, 1 Mar 2006, Joe Touch wrote:

> Vadim Antonov wrote:
> > On Wed, 1 Mar 2006, David P. Reed wrote:
> > 
> > The knowledge that connectivity is lost (i.e. that there's no *ability* to
> > send information before the need arises) is valuable.
> Perhaps, but that's not what TCP provides. TCP sends data reliably. If
> you aren't sending anything, there's nothing to complain about.

There is no such thing as just sending data reliably. All retransmission 
protocols do is trade off maximal latency for probability of delivery.

> As to "releasing resources", TCP preserves only the resources that
> affect sending data reliably. There's no utility to that end in cleaning
> up old connections; they're reset only when a new connection collides,
> which is in keeping with the concept that state needs to be adjusted
> only when it affects the reliable transmission of data.

Oh, I see. Did you ever consider that there are application servers which
have to carry, say, 20 megabytes of in-core state per a client connection?  
I did see such beauties.  Rete algorithm eats memory like hell, if you 
have enough facts to use.

Cleaning up stale or dead connections is something any half-respectable
app server does.


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