From user-return-12858-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Thu Jun 18 12:01:30 2020 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 3DFFC18065B for ; Thu, 18 Jun 2020 14:01:30 +0200 (CEST) Received: (qmail 13278 invoked by uid 500); 18 Jun 2020 12:01:29 -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 13260 invoked by uid 99); 18 Jun 2020 12:01:28 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd2-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 18 Jun 2020 12:01:28 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd2-us-west.apache.org (ASF Mail Server at spamd2-us-west.apache.org) with ESMTP id C1D5E1A4132 for ; Thu, 18 Jun 2020 12:01:27 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd2-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 0.101 X-Spam-Level: X-Spam-Status: No, score=0.101 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=0.2, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URI_HEX=0.1] autolearn=disabled Authentication-Results: spamd2-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 (spamd2-us-west.apache.org [10.40.0.9]) (amavisd-new, port 10024) with ESMTP id cLngZVBpRp5T for ; Thu, 18 Jun 2020 12:01:26 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2607:f8b0:4864:20::32f; helo=mail-ot1-x32f.google.com; envelope-from=eolivelli@gmail.com; receiver= Received: from mail-ot1-x32f.google.com (mail-ot1-x32f.google.com [IPv6:2607:f8b0:4864:20::32f]) by mx1-he-de.apache.org (ASF Mail Server at mx1-he-de.apache.org) with ESMTPS id ADF367DDEC for ; Thu, 18 Jun 2020 12:01:25 +0000 (UTC) Received: by mail-ot1-x32f.google.com with SMTP id g7so4260923oti.13 for ; Thu, 18 Jun 2020 05:01:25 -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; bh=gto6GEgKoQ+AXjzXbb345j1cz7AXaGdWax1+pOYXRig=; b=fa7LHEgZhhqSJG4imwb4gqux6HBlbS6cAeUu7lI5Om14dsfCYDLfSPTtGGNQ0/Rxm1 2b8h/djmkKE4Ju3Jvi+PHrgILa10OhzSxlxOOHdGnCSnMR6sCYMM+uaQPZr5ePaF51wg F09SZMIwEgokKtOOsTtI3Z53wpqbbgX91lNSYuXXDV5YGYAVlX6QhxHvpuqWCCTO5M3R BV6fyeWWrdCOPR0Qx+Y6FgUEd6O9XQD7gFZemuNctKPqfSuWyq74OCWP1go1UkGneRCC A8RBuM1hjvMK2wdRixeauG1KXpr+E7agJRScSAUi1Mf7sn5PKD0ziE4A+CnLdlHgGJuc qVTA== 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=gto6GEgKoQ+AXjzXbb345j1cz7AXaGdWax1+pOYXRig=; b=HWtBr35UHcKAlWUZPddwme4kGtd4ifFBmmAO4PgiF+S2+fHVRT1s6CTQG4rtkE5nc5 zk50exbq04S+hJJa3oocj5wihxldhXfxG2M7ipMlzMzYWWvirw4dwDZ/tRt/WlxSJpU6 R5YEVrsnwHGtoGya0LmRKQoMO7AKFZH0/tBurtPI0vqmZgOpFxVYGAVzkfJiM17kunKz PeRBx3iRsx303dsrJbu1IjcOebk8B//wriMmqKs54bHVrKcBevQe1eYWjtRMT3E8AOu/ A/eAdUPAzPNut7lDTgr7TNqfqbOZ7X9LfM+Kl84df1fg/SeKVI67ttQxpb9bAYUJaEjo XL/w== X-Gm-Message-State: AOAM5300yDZQw5m8HsgTbKN7SzKHX2w+1eBKs/FaG6CNShsFN/2PNO5R 52x05MfmupMcp0ZsaXt2kou7dRb2717tn9X6xwd+Fc3I X-Google-Smtp-Source: ABdhPJxvNlJA5qft4P2q43YAkEMYNi3UvJR2OILgksfvdrffhypiMThi0KHGJoyuUrnBcA4aprvo+GoCvvzhklS231Y= X-Received: by 2002:a05:6830:141:: with SMTP id j1mr3218078otp.318.1592481683189; Thu, 18 Jun 2020 05:01:23 -0700 (PDT) MIME-Version: 1.0 References: <72A9EA4D-9B78-4355-9BA7-9BA5C15727D4@jordanzimmerman.com> In-Reply-To: <72A9EA4D-9B78-4355-9BA7-9BA5C15727D4@jordanzimmerman.com> From: Enrico Olivelli Date: Thu, 18 Jun 2020 14:01:12 +0200 Message-ID: Subject: Re: How to deliberately cause a split brain? To: UserZooKeeper Content-Type: multipart/alternative; boundary="00000000000009b4a105a85a8968" --00000000000009b4a105a85a8968 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I told about using iptables only in order to create a network partition. If you want a simple split brain just switch every server in the cluster to standalone mode (comment server.xx lines) I saw it happening in production, it was so nasty :-( Enrico Il giorno gio 18 giu 2020 alle ore 13:50 Jordan Zimmerman < jordan@jordanzimmerman.com> ha scritto: > Way back in 2013 I wrote about a scenario whereby ZooKeeper will have two > leader nodes. I don=E2=80=99t know if it still applies but maybe it will = be helpful > to you: > http://zookeeper-user.578899.n2.nabble.com/Rolling-config-change-consider= ed-harmful-td7578761.html > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > Jordan Zimmerman > > > On Jun 18, 2020, at 4:07 AM, Tim Ward > wrote: > > > > =EF=BB=BFFrom: Szalay-Bek=C5=91 M=C3=A1t=C3=A9 > >> Honestly, I can not really think of any way to get split-brain. If > someone can, then let us know so that we can fix it ;) > > > > This issue arose because, apparently, we did get a split brain once upo= n > a time. The hints I've got however are that this happened in a pre-3.5 > version of Zookeeper, involving a (botched?) rescaling from 3 to 7 nodes. > From which hints I'm guessing that something got fixed in 3.5 so that thi= s > approach to deliberately provoking a split brain would not work with the > 3.5.7 we're now using. > > > > Tim Ward > > > > This message, and any files/attachments transmitted together with it, i= s > intended for the use only of the person (or persons) to whom it is > addressed. It may contain information which is confidential and/or > protected by legal privilege. Accordingly, any dissemination, distributio= n, > copying or use of this message, or any part of it or anything sent togeth= er > with it, other than by intended recipients, may constitute a breach of > civil or criminal law and is hereby prohibited. Unless otherwise stated, > any views expressed in this message are those of the person sending it an= d > not the sender's employer. No responsibility, legal or otherwise, of > whatever nature, is accepted as to the accuracy of the contents of this > message or for the completeness of the message as received. Anyone who is > not the intended recipient of this message is advised to make no use of i= t > and is requested to contact Featurespace Limited as soon as possible. Any > recipient of this message who has knowledge or suspects that it may have > been the subject of unauthorised interception or alteration is also > requested to contact Featurespace Limited. > --00000000000009b4a105a85a8968--