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<title>IPP Mail Archive: Re: PWG> IPP> PRO> HTTP Connection: close</title> <h1>Re: PWG> IPP> PRO> HTTP Connection: close</h1> Carl Kugler (kugler@us.ibm.com) Wed, 9 Sep 1998 16:53:39 -0400 <ul> <li> Messages sorted by: <a href="date.html#1225">[ date ]</a><a href="index.html#1225">[ thread ]</a><a href="subject.html#1225">[ subject ]</a><a href="author.html#1225">[ author ]</a>  <li> Next message: <a href="1226.html">henrik.holst@i-data.com: "IPP> Bake off"</a> <li> Previous message: <a href="1224.html">egglestn@lexmark.com: "IPP> Reply"</a>  </ul>  I agree that the client and server must accept the Connection: close he= ader. I'm wondering how to satisfy the requirement that the client and server= MUST include this header for the last operation in a sequence of operations.= Specifically, how do the client and server know, a priori, that the cur= rent operation is the last operation in a sequence (and therefore MUST inclu= de the Co nnection: close header)? -Carl rturner@sharplabs.com on 09/09/98 02:17:29 PM Please respond to rturner@sharplabs.com To: Carl Kugler/Boulder/IBM@ibmus cc: ipp@@pwg.org Subject: Re: PWG> IPP> PRO> HTTP Connection: close I tend to follow the saying "Be conservative in what you send, and libe= ral in what you accept..." Whether the text says MUST or not, IMHO we should be designing clients = and servers to handle a "connection: close" header whenever it is received and stil= l function normally, albeit with possibly less performance. Since I am not working on a client, I cannot speak for what clients are= or will actually do, but I do think the client end should drive the connection = status, whevever possible. Randy Carl Kugler wrote: > Section 4.1, General Headers, says > General Header: Connection > "close" only. Both client and server SHOULD keep a connection for the= > duration of a sequence of operations. The client and server MUST incl= ude this > header for the last operation in such a sequence. > Consider the (presumably typical) case of an interactive IPP client w= ith a user > interface. How is the client to know when the current operation is t= he last of > a sequence of user-initiated actions? Apparently, the only safe way = to sat isfy > the MUST (an absolute requirement of the specification) would be to s= end > "close" after each user-initiated action. But this would violate the= SHOULD, > and is contrary to the recommendations of "HTTP Connection Management= ", > <a href="http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-connection-00.t=">http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-connection-00.t=</a> xt > > Quoting: > "Authoritative knowledge that it is appropriate to close a connecti= on > can only come from the user. Unfortunately, that source is not to = be > trusted. First, most users don't know what a connection is, and > having them indicate it is okay to close it is meaningless. Second= , a > user that does know what a connection is probably inherently greed= y. > Such a user would never surrender the attention that a connection = to > a server implies. > But this is talking about the client actually closing the connection,= not > sending a header to the server to signal that the connection will be = closed > after completion of the response. Obviously, the header can only be s= ent as > part of a request. Also, "HTTP Connection Management" says clients S= HOULD > close connections before servers when possible. > How are you implementing this requirement? > > -Carl, =  <ul>  <li> Next message: <a href="1226.html">henrik.holst@i-data.com: "IPP> Bake off"</a> <li> Previous message: <a href="1224.html">egglestn@lexmark.com: "IPP> Reply"</a>  </ul>