Return-Path: Delivered-To: apmail-tomcat-users-archive@www.apache.org Received: (qmail 24636 invoked from network); 6 May 2009 19:20:14 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 6 May 2009 19:20:14 -0000 Received: (qmail 27618 invoked by uid 500); 6 May 2009 19:20:10 -0000 Delivered-To: apmail-tomcat-users-archive@tomcat.apache.org Received: (qmail 27575 invoked by uid 500); 6 May 2009 19:20:09 -0000 Mailing-List: contact users-help@tomcat.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: "Tomcat Users List" Delivered-To: mailing list users@tomcat.apache.org Received: (qmail 27564 invoked by uid 99); 6 May 2009 19:20:09 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 06 May 2009 19:20:09 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of aw@ice-sa.com designates 212.85.38.228 as permitted sender) Received: from [212.85.38.228] (HELO tor.combios.es) (212.85.38.228) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 06 May 2009 19:20:00 +0000 Received: from localhost (localhost [127.0.0.1]) by tor.combios.es (Postfix) with ESMTP id EEAD9226081 for ; Wed, 6 May 2009 21:17:14 +0200 (CEST) Received: from tor.combios.es ([127.0.0.1]) by localhost (tor.combios.es [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YC3+kaGgzJgO for ; Wed, 6 May 2009 21:17:14 +0200 (CEST) Received: from [192.168.245.129] (p549EB21F.dip0.t-ipconnect.de [84.158.178.31]) by tor.combios.es (Postfix) with ESMTPA id 9B6CF226080 for ; Wed, 6 May 2009 21:17:14 +0200 (CEST) Message-ID: <4A01E2B0.3010608@ice-sa.com> Date: Wed, 06 May 2009 21:19:12 +0200 From: =?ISO-8859-1?Q?Andr=E9_Warnier?= Reply-To: aw@ice-sa.com User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Tomcat Users List Subject: Re: Cluster session sync question (from documentation) References: <23411578.post@talk.nabble.com> <0AAE5AB84B013E45A7B61CB66943C17228615654B5@USEA-EXCH7.na.uis.unisys.com> <23413085.post@talk.nabble.com> <0AAE5AB84B013E45A7B61CB66943C17228615657E6@USEA-EXCH7.na.uis.unisys.com> In-Reply-To: <0AAE5AB84B013E45A7B61CB66943C17228615657E6@USEA-EXCH7.na.uis.unisys.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org Caldarale, Charles R wrote: >> From: lightbulb432 [mailto:veerukrishnan@hotmail.com] >> Subject: RE: Cluster session sync question (from documentation) >> >> Request 1 goes to node 1. Am I correct in saying that as long >> as Request 2 reaches node 2 before the session from node 1 has >> fully replicated over, the the inconsistent session problem exists? > > That's my understanding - which is why the doc says to use sticky sessions. > >> the session that persists would be either the session from >> node 1 or from node 2, but absolutely not both? > > Correct. > >> using what criteria would anyone decide against >> using them? What's the tradeoff here? > > Potential performance imbalance is the only thing I can think of. If one of your clients creates a lot of requests, they'll all have to be processed on a single node, leaving the others relatively idle. I doubt that this is much of a concern in the real world. > I can think of another : by using sticky sessions, you are forcing the load-balancer to keep track of which session belongs to which back-end, and to look up this table at each request. I could imagine that this could get tiresome.. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org For additional commands, e-mail: users-help@tomcat.apache.org