From owner-freebsd-hackers@FreeBSD.ORG Sat Apr 23 09:33:39 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id ED37E16A4CE for ; Sat, 23 Apr 2005 09:33:39 +0000 (GMT) Received: from szerver.siodigit.hu (ns.siodigit.hu [194.143.225.126]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2059A43D1F for ; Sat, 23 Apr 2005 09:33:39 +0000 (GMT) (envelope-from feczo@siodigit.hu) Received: from feczo.sdi.hu ([192.168.0.217]) by szerver.siodigit.hu with esmtp (Exim 4.50 (FreeBSD)) id 1DPH16-000NDp-7h; Sat, 23 Apr 2005 11:33:37 +0200 From: Feczak Szabolcs To: freebsd-hackers@freebsd.org In-Reply-To: <200504221811.49439.soralx@cydem.org> References: <1114193265.22867.3.camel@localhost.localdomain> <200504221811.49439.soralx@cydem.org> Content-Type: text/plain Organization: =?ISO-8859-1?Q?Si=F3digit?= Kft. Date: Sat, 23 Apr 2005 11:37:40 +0200 Message-Id: <1114249060.23167.9.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.1.1 Content-Transfer-Encoding: 7bit X-Spam-Score: -5.9 (-----) X-Spam-Report: Spam detection software: the administrator of that system for details. Content preview: On p, 2005-04-22 at 18:11 -0600, soralx@cydem.org create a failover cluster with two machines > > for a freebsd webserver with dynamic content > > runing apache with php, and postgresql. > > why can't this give you enough redundancy? [...] Content analysis details: (-5.9 points, 5.0 required) pts rule name description -------------------------------------------------- -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 1% [score: 0.0000] Subject: Re: Failover cluster for webserver with dynamic content ? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 23 Apr 2005 09:33:40 -0000 On p, 2005-04-22 at 18:11 -0600, soralx@cydem.org wrote: > > Anyway one step further, my question is > > How can I create a failover cluster with two machines > > for a freebsd webserver with dynamic content > > runing apache with php, and postgresql. > > why can't you have 2 separate machines accessing one mirrored RAID? > can't this give you enough redundancy? I thought about this, but I have several fears with that. First of all which machine would serve the RAID ? If this machine fails, than even though I have the second machine no use of it, since it does not have access to the data anymore. Second: how do I sync the sql database ... even though they use the same filesystem, some caching happens and when one of them writes back earlier what happens when to the other one tries to fsync. Although I do not have deep understanding of the postgresql system I have a fear that this threatens the data consistency.