From owner-freebsd-chat Thu Feb 13 23:10:48 2003 Delivered-To: freebsd-chat@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D6E7337B405 for ; Thu, 13 Feb 2003 23:10:46 -0800 (PST) Received: from stork.mail.pas.earthlink.net (stork.mail.pas.earthlink.net [207.217.120.188]) by mx1.FreeBSD.org (Postfix) with ESMTP id 038BA43F85 for ; Thu, 13 Feb 2003 23:10:45 -0800 (PST) (envelope-from tlambert2@mindspring.com) Received: from pool0261.cvx22-bradley.dialup.earthlink.net ([209.179.199.6] helo=mindspring.com) by stork.mail.pas.earthlink.net with asmtp (SSLv3:RC4-MD5:128) (Exim 3.33 #1) id 18jZze-0006Zu-00; Thu, 13 Feb 2003 23:10:43 -0800 Message-ID: <3E4C9612.2777D62E@mindspring.com> Date: Thu, 13 Feb 2003 23:09:06 -0800 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Brad Knowles Cc: Rahul Siddharthan , freebsd-chat@freebsd.org Subject: Re: Email push and pull (was Re: matthew dillon) References: <20030211032932.GA1253@papagena.rockefeller.edu> <3E498175.295FC389@mindspring.com> <3E49C434.D8D497EE@mindspring.com> <3E4A83BC.8A15E7C3@mindspring.com> <3E4B12F5.2608BBB@mindspring.com> <3E4BB64E.A9AEED28@mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-ELNK-Trace: b1a02af9316fbb217a47c185c03b154d40683398e744b8a4cf7f848d90f6bf143d51188ca6baf5fd666fa475841a1c7a350badd9bab72f9c350badd9bab72f9c Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Brad Knowles wrote: > At 7:14 AM -0800 2003/02/13, Terry Lambert wrote: > >> Okay, what parts of the problem doesn't Perdition solve? > > > > Replication and failover. > > True. But is the POP3/IMAP4 proxy really the best place to try > to solve this problem? No... but does proxy really solve anything, then, more than a DNS rotor solves? All it really does is add a single point of failure. Unless you can target a subset of back end content servers, you might as well use DNS round-robin. Using a proxy implies the back end replica problem is *already* solved. > > The result is that you provide a unified view onto a backend farm, > > but you lack replication and failover in the back-end, and it does > > not magically appear, merely because you are running Perdition. > > Fair enough. But how does this relate to the domain problem? > That's all you had mentioned previously. A proxy server doesn't solve the domain problem; Perdition was *your* answer to the domain problem. 8-). > > There are other POP3 and IMAP4 proxies that can do the same things > > Perdition can: it's no big deal. > > I've done some research in this area. I'd be interested to know > which ones you're talking about. The Cyrus one seems OK. Personally, I'd never use a proxy for this, except to front-end the authentication. Even then, it's somewhat of a tossup as to whether it really has any utility, unless it's capable of targetting a subset of the back end (in other words, it has a priori knowledge of where the replica lives; maybe it does LDAP lookups to select a backend server to point the client to). At that point, you are better taking the LARD/CARD approach, and adding "referral" to the IMAP4 protocol, and just handling it at the server level as a peering relationship, so the reason you'd do it is to avoid modifying client programs. > > In fact, it doesn't deal with > > LDAP, which is probably where the routing to the back end store will > > occur. > > Do I really need to quote the relevant sections of > perdition/db/ldap/perdition.schema, dated Mar 27, 2002? Maybe I should say "doesn't deal with LDAP the way it should" instead? -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message