From user-return-12088-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Wed Aug 21 18:19:22 2019 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 [207.244.88.153]) by mx-eu-01.ponee.io (Postfix) with SMTP id E4015180607 for ; Wed, 21 Aug 2019 20:19:21 +0200 (CEST) Received: (qmail 45144 invoked by uid 500); 21 Aug 2019 18:19:20 -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 45091 invoked by uid 99); 21 Aug 2019 18:19:20 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 21 Aug 2019 18:19:20 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id 8FE30C175C for ; Wed, 21 Aug 2019 18:01:34 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 3.804 X-Spam-Level: *** X-Spam-Status: No, score=3.804 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=2, KAM_BADIPHTTP=2, NORMAL_HTTP_TO_IP=0.001, NUMERIC_HTTP_ADDR=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, WEIRD_PORT=0.001] autolearn=disabled Authentication-Results: spamd1-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx1-he-de.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id T8TO9itg9HB0 for ; Wed, 21 Aug 2019 18:01:32 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2607:f8b0:4864:20::32c; helo=mail-ot1-x32c.google.com; envelope-from=eolivelli@gmail.com; receiver= Received: from mail-ot1-x32c.google.com (mail-ot1-x32c.google.com [IPv6:2607:f8b0:4864:20::32c]) by mx1-he-de.apache.org (ASF Mail Server at mx1-he-de.apache.org) with ESMTPS id 9C3657DD52 for ; Wed, 21 Aug 2019 18:01:31 +0000 (UTC) Received: by mail-ot1-x32c.google.com with SMTP id g17so2924896otl.2 for ; Wed, 21 Aug 2019 11:01:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7qmP5RvcHZpQaWqhLRL9eQjVE6KBzYwW43Rje/ndo4U=; b=Xmz5SYUchUGHnpJeMOkQWujD9heVQWyzZneuBxwP+ZX9YpgPaGszRQVZMe9jo/v1W6 7Rk+EWdaDUOC+5KYB+zmH02yYwwshUm35MWVRBvfW4O0HocZ3kd8r5MSXdX4asroX3dd EpmJfCOUYAr6zXxqh1+3Y4sSIkUQTBKr0wE2M5xHKTFn7aw3tJiffbYaed6GttGPtNek jjNq/oRS17Sw/URvXt7Wh0SasjNiwkKrxgnJOjiycZO08lyBJwRLT+L7wpBZgk1wNa8q CLiy1DN7dKX8HRqZKc2tjvovPnbZD0UxRfH/dePgT4OqM2+CaQOI6q6WUsR+2H1x7FHJ LEiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7qmP5RvcHZpQaWqhLRL9eQjVE6KBzYwW43Rje/ndo4U=; b=WviUHD6Vzjri82nc5Q+bEn3ncKTHFvvvO/Y0SJqjCXelRxuzt4UTiHeHM4gnIaJ/cc DBOXCjeFDC7IGY9yLD3PredjcjNRBwIRYuilLDPZMbe8K/8O2/qzDcxn0TtAhVYzGygr 6o0xjlyRtkJUkHH2WbM0jgrrlP0G3FOQIbCXhDBpnqY8A11NnjCVsHcmf6xKlrM08Ff+ 0J3+wta4bFE5ezSOtw+6zePJ0+nyn2igv5uOxDcexT6ScmXn6bGUkDc0nhDGYl/0bsPy UQ1mEfaTlCMitb9Fo8TYn878Y2M5uLLkcsVnOw5N56HhiZmxPMnY6p1mooyqYU2FgvVv MowA== X-Gm-Message-State: APjAAAVw2OhoqFZTjupKsorPAKozTdQ0I6H7hasLLzAATAG+uXF/sjP5 X0cI1Lqy4B1hJmdKbMrykvLm3nvlzPbL4owSylLmng== X-Google-Smtp-Source: APXvYqyFqm8x1DO30D8JXCBlorryiAIaZnYhrP4gvOeiBVv/f2YvXHEqyZbDljhvSqHYAPta/oOmP4+vgMsXCDS67gM= X-Received: by 2002:a9d:4c18:: with SMTP id l24mr26189913otf.168.1566410490116; Wed, 21 Aug 2019 11:01:30 -0700 (PDT) MIME-Version: 1.0 References: <16cb4ac9140.27db.495a588ebf64bb63541fbe4ec3b29808@gmail.com> In-Reply-To: From: Enrico Olivelli Date: Wed, 21 Aug 2019 20:01:17 +0200 Message-ID: Subject: Re: About ZooKeeper Dynamic Reconfiguration To: user@zookeeper.apache.org Cc: Cee Tee Content-Type: multipart/alternative; boundary="000000000000d60d030590a45ceb" --000000000000d60d030590a45ceb Content-Type: text/plain; charset="UTF-8" Il mer 21 ago 2019, 17:22 Alexander Shraer ha scritto: > That's great! Thanks for sharing. > > > Added benefit is that we can also control which data center gets the > quorum > > in case of a network outage between the two. > > Can you explain how this works? In case of a network outage between two > DCs, one of them has a quorum of participants and the other doesn't. > The participants in the smaller set should not be operational at this time, > since they can't get quorum. no ? > I have recently talked about a similar problem with Norbert K. on gitter chat. We got to the conclusion that you need 3 datacenters Enrico > Thanks, > Alex > > On Wed, Aug 21, 2019 at 7:55 AM Cee Tee wrote: > > > We have solved this by implementing a 'zookeeper cluster balancer', it > > calls the admin server api of each zookeeper to get the current status > and > > will issue dynamic reconfigure commands to change dead servers into > > observers so the quorum is not in danger. Once the dead servers > reconnect, > > they take the observer role and are then reconfigured into participants > > again. > > > > Added benefit is that we can also control which data center gets the > > quorum > > in case of a network outage between the two. > > Regards > > Chris > > > > On 21 August 2019 16:42:37 Alexander Shraer wrote: > > > > > Hi, > > > > > > Reconfiguration, as implemented, is not automatic. In your case, when > > > failures happen, this doesn't change the ensemble membership. > > > When 2 of 5 fail, this is still a minority, so everything should work > > > normally, you just won't be able to handle an additional failure. If > > you'd > > > like > > > to remove them from the ensemble, you need to issue an explicit > > > reconfiguration command to do so. > > > > > > Please see details in the manual: > > > https://zookeeper.apache.org/doc/r3.5.5/zookeeperReconfig.html > > > > > > Alex > > > > > > On Wed, Aug 21, 2019 at 7:29 AM Gao,Wei wrote: > > > > > >> Hi > > >> I encounter a problem which blocks my development of load balance > > using > > >> ZooKeeper 3.5.5. > > >> Actually, I have a ZooKeeper cluster which comprises of five zk > > >> servers. And the dynamic configuration file is as follows: > > >> > > >> server.1=zk1:2888:3888:participant;0.0.0.0:2181 > > >> server.2=zk2:2888:3888:participant;0.0.0.0:2181 > > >> server.3=zk3:2888:3888:participant;0.0.0.0:2181 > > >> server.4=zk4:2888:3888:participant;0.0.0.0:2181 > > >> server.5=zk5:2888:3888:participant;0.0.0.0:2181 > > >> > > >> The zk cluster can work fine if every member works normally. > However, > > if > > >> say two of them are suddenly down without previously being notified, > > >> the dynamic configuration file shown above will not be synchronized > > >> dynamically, which leads to the zk cluster fail to work normally. > > >> I think this is a very common case which may happen at any time. If > > so, > > >> how can we resolve it? > > >> Really look forward to hearing from you! > > >> Thanks > > >> > > > > > > > > > --000000000000d60d030590a45ceb--