From dev-return-28640-apmail-directory-dev-archive=directory.apache.org@directory.apache.org Tue Jan 20 03:29:44 2009 Return-Path: Delivered-To: apmail-directory-dev-archive@www.apache.org Received: (qmail 58868 invoked from network); 20 Jan 2009 03:29:44 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 20 Jan 2009 03:29:44 -0000 Received: (qmail 91387 invoked by uid 500); 20 Jan 2009 03:29:43 -0000 Delivered-To: apmail-directory-dev-archive@directory.apache.org Received: (qmail 91343 invoked by uid 500); 20 Jan 2009 03:29:43 -0000 Mailing-List: contact dev-help@directory.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: "Apache Directory Developers List" Delivered-To: mailing list dev@directory.apache.org Received: (qmail 91334 invoked by uid 99); 20 Jan 2009 03:29:43 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 19 Jan 2009 19:29:43 -0800 X-ASF-Spam-Status: No, hits=1.2 required=10.0 tests=FS_REPLICA,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [69.145.82.195] (HELO skunk.mtbrook.bozemanpass.com) (69.145.82.195) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 20 Jan 2009 03:29:34 +0000 Received: from [69.145.82.252] (unknown [69.145.82.252]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by skunk.mtbrook.bozemanpass.com (Postfix) with ESMTP id C9167558041 for ; Mon, 19 Jan 2009 19:29:12 -0800 (PST) Message-ID: <49754501.1030500@bozemanpass.com> Date: Mon, 19 Jan 2009 20:29:05 -0700 From: David Boreham User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: Apache Directory Developers List Subject: Re: [Replication] Using time offsets instead of absolute time References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org It's 2009 not 1989. Systems need correct time anyway. Many other replication systems require synchronized clocks. Don't attempt to solve this problem yourself, use NTP. Alex Karasulu wrote: > Hi all, > > The first thread on replication after Emmanuel's comments started > taking a turn towards the question of time synchronization across > replicating servers. Time synchronization is very nice to have and > forget about while writing the code around replication. And yes we do > not have control over it since administrators can fudge this up. > > Another alternative would be to have all the servers in the cluster > communicate with one another on occasion to share their current time > to establish offsets. These offsets (differences in time) between > servers in replication agreements can be used to correct for any time > variance we might encounter. Furthermore if the time is adjusted on > the hosts, the cluster can adjust to time changes. > > WDYT? > > Alex