Return-Path: X-Original-To: apmail-jackrabbit-oak-dev-archive@minotaur.apache.org Delivered-To: apmail-jackrabbit-oak-dev-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id E643C10198 for ; Tue, 16 Apr 2013 09:50:14 +0000 (UTC) Received: (qmail 67103 invoked by uid 500); 16 Apr 2013 09:50:13 -0000 Delivered-To: apmail-jackrabbit-oak-dev-archive@jackrabbit.apache.org Received: (qmail 66900 invoked by uid 500); 16 Apr 2013 09:50:09 -0000 Mailing-List: contact oak-dev-help@jackrabbit.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: oak-dev@jackrabbit.apache.org Delivered-To: mailing list oak-dev@jackrabbit.apache.org Received: (qmail 66851 invoked by uid 99); 16 Apr 2013 09:50:07 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 16 Apr 2013 09:50:07 +0000 X-ASF-Spam-Status: No, hits=-1.6 required=5.0 tests=RCVD_IN_DNSWL_MED,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [64.18.1.23] (HELO exprod6og109.obsmtp.com) (64.18.1.23) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 16 Apr 2013 09:50:00 +0000 Received: from outbound-smtp-2.corp.adobe.com ([193.104.215.16]) by exprod6ob109.postini.com ([64.18.5.12]) with SMTP ID DSNKUW0es44jcH9UlmG/KBc/am5Bj6zTtMdJ@postini.com; Tue, 16 Apr 2013 02:49:40 PDT Received: from inner-relay-1.corp.adobe.com (inner-relay-1.corp.adobe.com [153.32.1.51]) by outbound-smtp-2.corp.adobe.com (8.12.10/8.12.10) with ESMTP id r3G9nb99012104 for ; Tue, 16 Apr 2013 02:49:38 -0700 (PDT) Received: from nacas02.corp.adobe.com (nacas02.corp.adobe.com [10.8.189.100]) by inner-relay-1.corp.adobe.com (8.12.10/8.12.10) with ESMTP id r3G9nbAV022728 for ; Tue, 16 Apr 2013 02:49:37 -0700 (PDT) Received: from eurhub01.eur.adobe.com (10.128.4.30) by nacas02.corp.adobe.com (10.8.189.100) with Microsoft SMTP Server (TLS) id 8.3.298.1; Tue, 16 Apr 2013 02:49:37 -0700 Received: from susi.local (10.136.129.23) by eurhub01.eur.adobe.com (10.128.4.111) with Microsoft SMTP Server id 8.3.298.1; Tue, 16 Apr 2013 10:49:35 +0100 Message-ID: <516D1EB0.4010706@apache.org> Date: Tue, 16 Apr 2013 10:49:36 +0100 From: =?UTF-8?B?TWljaGFlbCBEw7xyaWc=?= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: Subject: Re: Scalability of JCR observation References: <51680DA2.7010403@apache.org> In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Checked: Checked by ClamAV on apache.org On 15.4.13 9:32, Bertrand Delacretaz wrote: > Hi, > > On Fri, Apr 12, 2013 at 3:35 PM, Michael Dürig wrote: >> An implementation approach for backward compatible observation is to use a >> commit hook to record the required changes to a journal (e.g. >> /jcr:system/rep:observation). Observation listeners would then later >> generate the observation events by scrapping that journal asynchronously... > > This sounds a lot like a distributed message queue... Right. > >> ...A somewhat open question is how this should work across the cluster... > > So I'm wondering if using an existing distributed message queue > service (ActiveMQ/RabbitMQ etc) would help implement this. IIUC this > is only a problem in very large Oak setups, so having to install > additional components might not be an issue. Yes I think we can do that. In a first step I'd like to have an implementation entirely internal to Oak so we can validate it against our basic use cases. Further down the line we can abstract over the underlying queueing mechanism such that other backends could be pugged in. Michael > > -Bertrand >