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Re: #131: Connection limits (proposal)

From: William A. Rowe, Jr. <wrowe@rowe-clan.net>
Date: Sun, 18 Oct 2009 23:55:46 -0500
Message-ID: <4ADBF152.3010300@rowe-clan.net>
To: Adrien de Croy <adrien@qbik.com>
CC: Mark Nottingham <mnot@mnot.net>, HTTP Working Group <ietf-http-wg@w3.org>
Adrien de Croy wrote:
> So I believe the best place to restrict usage is at the server, where
> the operator then has a choice about how much service will be provided. 
> Putting a responsibility on the client takes away this choice from the
> server operator.

Which says nothing about the client expectations, which was the point of my
initial response.  The responsibility has been assumed by servers and their
intermediate firewalls/load balancers to ferret out abusive traffic.  Any
poorly constructed client can and will fall into such traps.

> So, what about something like:
> "Implementors of client applications SHOULD give consideration to
> effects that a client's use of resources may have on the network (both
> local and non-local), and design clients to act responsibly within any
> network they participate in.  Some intermediaries and servers are known
> to limit the number of concurrent connections, or rate of requests.  An
> excessive number of connections has also been known to cause issues on
> congested shared networks.  In the past HTTP has recommended a maximum
> number of concurrent connections a client should make, however this
> limit has also caused problems in some applications.  It is also
> believed that any recommendation on number of concurrent connections
> made now will not apply properly to all applications, and will become
> obsolete with advances in technology."

This does not address my specific concern, which is to beat into the implementors
heads not to aggressively retry parallel connections where none will be permitted;

>> Is it worthwhile to add the caveat;
>> """
>> Clients attempting to establish simultaneous connections SHOULD anticipate
>> the server to reject excessive attempts to establish additional connections,
>> and gracefully degrade to passing all requests through the successfully
>> established connection(s), rather than retrying.
>> """

We appear to be in agreement, but addressing two different aspects of the same.
Received on Monday, 19 October 2009 04:56:22 UTC

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