From user-return-11627-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Tue Aug 21 11:29:55 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 6F765180630 for ; Tue, 21 Aug 2018 11:29:54 +0200 (CEST) Received: (qmail 2634 invoked by uid 500); 21 Aug 2018 09:29:53 -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 2622 invoked by uid 99); 21 Aug 2018 09:29:52 -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; Tue, 21 Aug 2018 09:29:52 +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 267DAC92DA for ; Tue, 21 Aug 2018 09:29:52 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.888 X-Spam-Level: * X-Spam-Status: No, score=1.888 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, T_DKIMWL_WL_MED=-0.01] autolearn=disabled Authentication-Results: spamd1-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id 2egrpEm0qedL for ; Tue, 21 Aug 2018 09:29:49 +0000 (UTC) Received: from mail-ua1-f48.google.com (mail-ua1-f48.google.com [209.85.222.48]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTPS id BA1C05F3CE for ; Tue, 21 Aug 2018 09:29:48 +0000 (UTC) Received: by mail-ua1-f48.google.com with SMTP id y10-v6so11448855uao.4 for ; Tue, 21 Aug 2018 02:29:48 -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=PCfgW/VCW9VYOGAwq2YAP6Bbsgw4xDn8Q7/pA5rPkXI=; b=Y7W77NHalzi2Et3/Uivs+x28RtuioITkaHaFt2OTWp3XeRzm9bIShCgqO7h+SNYGDO biBSnqnP8mI3hrfm/rv/aahfEa1SYZf8zKpxQDpANi0I5LsD3OnTvgeE9AEL67kAleQp IUvUkFT1nuRdFrV2hJDUEi9aKOy77nxUb7r2jBtb90pPU/+pkBSMHWLioxDvXc/z3vT5 Ir2pTbyaNRbtDPeOka1hunzKmXHU/zBrWC71gJPAIuPvw7sPflVyBoODHGvz5prs/stw ODI7A2V29mb3rxY4xGvSpTB+EoowIbhpDm5DT89/kvYLVpEPFKQOIyZM4e6/jZqDVivh JH0Q== 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=PCfgW/VCW9VYOGAwq2YAP6Bbsgw4xDn8Q7/pA5rPkXI=; b=mAq+6MBhSMfHdZZw1wwKURO766GM8bFR+PnXVnQGeiiY8uIh/bBDWSOwVjYXbJRMlC drwsnrVBjWOGxSWD2tHL1W/t1rTH1EQy2VR1PowBopvnnLTfLsVTrfg8W3X2H5WDvVPZ /Aw6eHF/2AtBn/HxnoHsl1Ro22OlEJBZTUCtHkydGwahaMXWxqpk5IsQGZQbs2pWOe7o KPacrvqmj8UPBjVR7lzkQc4q6I4yjWc+yMqPSi9CdoQN35O4tA23fcsZMLoXcjtHDMQx +HoaB4iRKsM2YME4ljs+zTXck5fqgBoCCHtNmxuUbxkVIfMm6pLqdAO5OOfjvos9LV4h VwNw== X-Gm-Message-State: AOUpUlEVoNSqgea3URwGs+JRHnFzwrMZeYTODIoJ5r6UIWJMExOXzlt9 fXHdd8wMw+lM26FqQT0tkb7gKf+XtU3CBgVoK5TLVA== X-Google-Smtp-Source: AA+uWPzQc62v5A8FDUljiRRnTrRWPpvrudpP2utITKeqhCBngW2q7ZNtgPrCV7mmngOKoXYC+OSBDaPFk8NA8bmUgu4= X-Received: by 2002:ab0:5b8f:: with SMTP id y15-v6mr31885298uae.59.1534843782210; Tue, 21 Aug 2018 02:29:42 -0700 (PDT) MIME-Version: 1.0 References: <1651a05f250.276d.495a588ebf64bb63541fbe4ec3b29808@gmail.com> <1651a161ef0.276d.495a588ebf64bb63541fbe4ec3b29808@gmail.com> In-Reply-To: From: Cee Tee Date: Tue, 21 Aug 2018 11:29:30 +0200 Message-ID: Subject: Re: Leader election failing To: user@zookeeper.apache.org Content-Type: multipart/alternative; boundary="0000000000006ca8a50573eeaa5d" --0000000000006ca8a50573eeaa5d Content-Type: text/plain; charset="UTF-8" I've tested the patch and let it run 6 days. It did not help, result is still the same. (remaining ZKs form islands based on datacenter they are in). I have mitigated it by doing a daily rolling restart. Regards, Chris On Mon, Aug 13, 2018 at 2:06 PM Andor Molnar wrote: > Hi Chris, > > Would you mind testing the following patch on your test clusters? > I'm not entirely sure, but the issue might be related. > > https://issues.apache.org/jira/browse/ZOOKEEPER-2930 > > Regards, > Andor > > > > On Wed, Aug 8, 2018 at 6:51 PM, Camille Fournier > wrote: > > > If you have the time and inclination, next time you see this problem in > > your test clusters get stack traces and any other diagnostics possible > > before restarting. I'm not an expert at network debugging but if you have > > someone who is you might want them to take a look at the connections and > > settings of any switches/firewalls/etc involved, see if there's any > unusual > > configurations or evidence of other long-lived connections failing (even > if > > their services handle the failures more gracefully). Send us the stack > > traces also it would be interesting to take a look. > > > > C > > > > > > On Wed, Aug 8, 2018, 11:09 AM Chris wrote: > > > > > Running 3.5.5 > > > > > > I managed to recreate it on acc and test cluster today, failing on > > > shutdown > > > of leader. Both had been running for over a week. After restarting all > > > zookeepers it runs fine no matter how many leader shutdowns i throw at > > it. > > > > > > On 8 August 2018 5:05:34 pm Andor Molnar > > > wrote: > > > > > > > Some kind of a network split? > > > > > > > > It looks like 1-2 and 3-4 were able to communicate each other, but > > > > connection timed out between these 2 splits. When 5 came back online > it > > > > started with supporters of (1,2) and later 3 and 4 also joined. > > > > > > > > There was no such issue the day after. > > > > > > > > Which version of ZooKeeper is this? 3.5.something? > > > > > > > > Regards, > > > > Andor > > > > > > > > > > > > > > > > On Wed, Aug 8, 2018 at 4:52 PM, Chris wrote: > > > > > > > >> Actually i have similar issues on my test and acceptance clusters > > where > > > >> leader election fails if the cluster has been running for a couple > of > > > days. > > > >> If you stop/start the Zookeepers once they will work fine on further > > > >> disruptions that day. Not sure yet what the treshold is. > > > >> > > > >> > > > >> On 8 August 2018 4:32:56 pm Camille Fournier > > > wrote: > > > >> > > > >> Hard to say. It looks like about 15 minutes after your first > incident > > > where > > > >>> 5 goes down and then comes back up, servers 1 and 2 get socket > errors > > > to > > > >>> their connections with 3, 4, and 6. It's possible if you had waited > > > those > > > >>> 15 minutes, once those errors cleared the quorum would've formed > with > > > the > > > >>> other servers. But as for why there were those errors in the first > > > place > > > >>> it's not clear. Could be a network glitch, or an obscure bug in the > > > >>> connection logic. Has anyone else ever seen this? > > > >>> If you see it again, getting a stack trace of the servers when they > > > can't > > > >>> form quorum might be helpful. > > > >>> > > > >>> On Wed, Aug 8, 2018 at 11:52 AM Cee Tee > > wrote: > > > >>> > > > >>> I have a cluster of 5 participants (id 1-5) and 1 observer (id 6). > > > >>>> 1,2,5 are in datacenter A. 3,4,6 are in datacenter B. > > > >>>> Yesterday one of the participants (id5, by chance was the leader) > > was > > > >>>> rebooted. Although all other servers were online and not suffering > > > from > > > >>>> networking issues the leader election failed and the cluster > > remained > > > >>>> "looking" until the old leader came back online after which it was > > > >>>> promptly > > > >>>> elected as leader again. > > > >>>> > > > >>>> Today we tried the same exercise on the exact same servers, 5 was > > > still > > > >>>> leader and was rebooted, and leader election worked fine with 4 as > > new > > > >>>> leader. > > > >>>> > > > >>>> I have included the logs. From the logs i see that yesterday 1,2 > > > never > > > >>>> received new leader proposals from 3,4 and vice versa. > > > >>>> Today all proposals came through. This is not the first time we've > > > seen > > > >>>> this type of behavior, where some zookeepers can't seem to find > each > > > >>>> other > > > >>>> after the leader goes down. > > > >>>> All servers use dynamic configuration and have the same config > node. > > > >>>> > > > >>>> How could this be explained? These servers also host a replicated > > > >>>> database > > > >>>> cluster and have no history of db replication issues. > > > >>>> > > > >>>> Thanks, > > > >>>> Chris > > > >>>> > > > >>>> > > > >>>> > > > >>>> > > > >> > > > >> > > > >> > > > > > > > > > > > > > > > --0000000000006ca8a50573eeaa5d--