From user-return-11633-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Wed Aug 22 21:54:34 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id A94AA180662 for ; Wed, 22 Aug 2018 21:54:33 +0200 (CEST) Received: (qmail 20296 invoked by uid 500); 22 Aug 2018 19:54:32 -0000 Mailing-List: contact user-help@zookeeper.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@zookeeper.apache.org Delivered-To: mailing list user@zookeeper.apache.org Received: (qmail 20277 invoked by uid 99); 22 Aug 2018 19:54:31 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd3-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 22 Aug 2018 19:54:31 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd3-us-west.apache.org (ASF Mail Server at spamd3-us-west.apache.org) with ESMTP id 6591D1809DF for ; Wed, 22 Aug 2018 19:54:31 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd3-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -0.102 X-Spam-Level: X-Spam-Status: No, score=-0.102 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd3-us-west.apache.org (amavisd-new); dkim=pass (1024-bit key) header.d=elyograg.org Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd3-us-west.apache.org [10.40.0.10]) (amavisd-new, port 10024) with ESMTP id J4f00RDuNJ4W for ; Wed, 22 Aug 2018 19:54:29 +0000 (UTC) Received: from frodo.elyograg.org (frodo.elyograg.org [166.70.79.217]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id BE3B55F36D for ; Wed, 22 Aug 2018 19:54:28 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by frodo.elyograg.org (Postfix) with ESMTP id CF7CA2270 for ; Wed, 22 Aug 2018 13:54:20 -0600 (MDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=elyograg.org; h= content-language:content-transfer-encoding:content-type :content-type:in-reply-to:mime-version:user-agent:date:date :message-id:from:from:references:subject:subject:received :received; s=mail; t=1534967660; bh=VQETBj1kS0E4HrUsENFmYStlxgnM urGRLtAq64dakZ8=; b=lM7QDIiTzWWcFJd5lBcJLasyUMQFBYtR0fRbzQuR2tQE xqcCwWwfqEqO/4XIq1spBMHegAW87Z4LtpEGY5/Y0XiHBaSaJ5q7R/pc+oK/VMaR WgtlSqf+R5NZa6uMrNgD5FlH7qklVNCTzwybU+uXFzmygQ5RKk4RyykkCXpCl8Q= X-Virus-Scanned: Debian amavisd-new at frodo.elyograg.org Received: from frodo.elyograg.org ([127.0.0.1]) by localhost (frodo.elyograg.org [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id oVZq7gFZMJbZ for ; Wed, 22 Aug 2018 13:54:20 -0600 (MDT) Received: from [192.168.1.114] (114.int.elyograg.org [192.168.1.114]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: elyograg@elyograg.org) by frodo.elyograg.org (Postfix) with ESMTPSA id 7D6FC1CF5 for ; Wed, 22 Aug 2018 13:54:20 -0600 (MDT) Subject: Re: ZooKeeper in different datacenters To: user@zookeeper.apache.org References: <1534953733108-0.post@n2.nabble.com> <2f768215-0b92-0d52-39cb-a8d23bd1b990@elyograg.org> <1534957823339-0.post@n2.nabble.com> From: Shawn Heisey Message-ID: <38da1604-4d1a-af9e-dffe-e8de15e30b90@elyograg.org> Date: Wed, 22 Aug 2018 13:54:21 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1534957823339-0.post@n2.nabble.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US On 8/22/2018 11:10 AM, ilango dhandapani wrote: > So, if I have 3 zk servers on 1st DC, 2 solr servers on 1st DC and 2 solr > servers on 2nd DC, this will work right ? Other than network/latency between > DC1 and DC2 for solr replication. No.  This is what I was trying to tell you. With half your ZK servers in one DC and half in the other, if you lose either datacenter, ZK loses quorum, and SolrCloud switches to read-only.  If you still have a complete copy of your indexes, you'll be able to continue making queries, but you will be unable to make any changes to any index until the datacenter comes back up.  When there are six ZK servers, you must have at least four of them operational and reachable, or you do not have quorum. For fault tolerance on ZK, you need at least three data centers.  So that if you lose any datacenter, quorum can still be maintained with the ZK servers in the other two datacenters. Thanks, Shawn