From dev-return-76523-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Fri Dec 7 03:03:24 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 BDC1C180674 for ; Fri, 7 Dec 2018 03:03:23 +0100 (CET) Received: (qmail 42728 invoked by uid 500); 7 Dec 2018 02:03:22 -0000 Mailing-List: contact dev-help@zookeeper.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@zookeeper.apache.org Delivered-To: mailing list dev@zookeeper.apache.org Received: (qmail 42715 invoked by uid 99); 7 Dec 2018 02:03:21 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd4-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 07 Dec 2018 02:03:21 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd4-us-west.apache.org (ASF Mail Server at spamd4-us-west.apache.org) with ESMTP id 79E84C047E for ; Fri, 7 Dec 2018 02:03:21 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd4-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.797 X-Spam-Level: * X-Spam-Status: No, score=1.797 tagged_above=-999 required=6.31 tests=[DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd4-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx1-lw-us.apache.org ([10.40.0.8]) by localhost (spamd4-us-west.apache.org [10.40.0.11]) (amavisd-new, port 10024) with ESMTP id BB3ezURdLcG8 for ; Fri, 7 Dec 2018 02:03:18 +0000 (UTC) Received: from mail-it1-f171.google.com (mail-it1-f171.google.com [209.85.166.171]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTPS id B261660FDE for ; Fri, 7 Dec 2018 02:03:17 +0000 (UTC) Received: by mail-it1-f171.google.com with SMTP id b5so4852217iti.2 for ; Thu, 06 Dec 2018 18:03:17 -0800 (PST) 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; bh=qf/iUkJX6d4yM6row8uDTTcQ9/YjJT2UakDa4Zj4gCI=; b=lG766go/d98Z1opQ4U2DrD8/4NbC3bisM1A3wKrWSJ4AskFFAnH5RoUh1gKhcMI8EF /k4byVod5aIKX2MdPzvIVVVlfU6wtwNJc/kXmHkOlI8cX1JQU6YG0uRswkf5T2MKiiyZ mG3dsGzkGLeLa39B5xZvzEMudYqGTUkscC3Ivvixh/rGoVb7qau8uoxAF1x6CPJIDLPA ItsT3vxepljY8eBl2/GDtV0ni7ElF4tmWJLVH9DQ8FsURX38oNmRC8uIRuG5qbYWX9ao LFomC7HANeDu7qHiXN1P1a0a8lCb+x3dVvgsVrBlP9qyRZpb6h0fWy3lZao2H8sKHVTt oUsg== 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; bh=qf/iUkJX6d4yM6row8uDTTcQ9/YjJT2UakDa4Zj4gCI=; b=KuLPZh20eN9xHPVueMDOlUJVeLTAk0yFsOdmbdMubpk97wxZW+6Jh3G/a6EypvoQkE /v+A4kTaOTv0E0aBb3nPmXWHio6OhuLsR0bb9/YjDghPR9lxQrCu6yHwAbR4O0XzMRQ7 7DEG1eB5bYxbSUZARCt8YHtDlRuvWul6WeOhGnZhuWPHFOXPv/ZCvR9s29AvLp28KQya 7JOPTX6V8N5bICv4b3KCTarKJjc0aa93fJ6evwd8Tg/f6t/e2DuW0GYieXMDDmV7pYlT UrZP2ZywqiyTtLqHYq8LNPMroHvfnlaPBowNcazSyhXkogRV6XMRDs+UaOmWeSDa33X+ MacA== X-Gm-Message-State: AA+aEWZTN7EBC6k+3E++xKpSEEFP88tNn40tuZf715v2SLrGT+/psGO2 w3DZ4+vXkkuDGXgYalmTPa8WEGbJaQxxNgk5NXDATw== X-Google-Smtp-Source: AFSGD/UkgHwrdZY7+rvLkCP+BoJHGifw9YrBSKZu9CW91fl44CWMKH0ZBJkn+g54KYiocb7+NlfJvqVdh77dx0ACwdo= X-Received: by 2002:a24:d04:: with SMTP id 4mr654295itx.19.1544148196697; Thu, 06 Dec 2018 18:03:16 -0800 (PST) MIME-Version: 1.0 References: <2AB495FA-0239-4293-94AB-F9F6CC425BEA@jordanzimmerman.com> <5464F3BD-71EE-497E-A72E-90BB9474D6EF@jordanzimmerman.com> In-Reply-To: <5464F3BD-71EE-497E-A72E-90BB9474D6EF@jordanzimmerman.com> From: Michael Borokhovich Date: Thu, 6 Dec 2018 18:02:49 -0800 Message-ID: Subject: Re: Leader election To: dev@zookeeper.apache.org Content-Type: multipart/alternative; boundary="000000000000beaef9057c650400" --000000000000beaef9057c650400 Content-Type: text/plain; charset="UTF-8" We are planning to run Zookeeper nodes embedded with the client nodes. I.e., each client runs also a ZK node. So, network partition will disconnect a ZK node and not only the client. My concern is about the following statement from the ZK documentation: "Timeliness: The clients view of the system is guaranteed to be up-to-date within a certain time bound. (*On the order of tens of seconds.*) Either system changes will be seen by a client within this bound, or the client will detect a service outage." What are these "*tens of seconds*"? Can we reduce this time by configuring "syncLimit" and "tickTime" to let's say 5 seconds? Can we have a strong guarantee on this time bound? On Thu, Dec 6, 2018 at 1:05 PM Jordan Zimmerman wrote: > > Old service leader will detect network partition max 15 seconds after it > > happened. > > If the old service leader is in a very long GC it will not detect the > partition. In the face of VM pauses, etc. it's not possible to avoid 2 > leaders for a short period of time. > > -JZ --000000000000beaef9057c650400--