From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B120C3A59D for ; Fri, 16 Aug 2019 18:23:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1A4E22077C for ; Fri, 16 Aug 2019 18:23:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=web.de header.i=@web.de header.b="kM/MXhgb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A4E22077C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=web.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hygt0-0008Ce-3D for qemu-devel@archiver.kernel.org; Fri, 16 Aug 2019 14:23:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37386) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hygq4-0007ei-Pk for qemu-devel@nongnu.org; Fri, 16 Aug 2019 14:20:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hygq3-0001hZ-FM for qemu-devel@nongnu.org; Fri, 16 Aug 2019 14:20:36 -0400 Received: from mout.web.de ([212.227.15.3]:44659) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hygq3-0001gL-3X for qemu-devel@nongnu.org; Fri, 16 Aug 2019 14:20:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1565979610; bh=JDfhIzb9J58E6cI38r2EQYf4Qz2YFCr2E3z843HDURM=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject:In-Reply-To:References; b=kM/MXhgbQcgQddhlCO/giTHsurhkVL8ycXbE8Q9Rqr0h7+GJm8214l6jM0eXKovCq 9SUbcI0wJ3sdZY5Z4Pg9Zm8o1dIdAkKlXBy53VtiUy9Ionq0k0jfPTHzNPaYAX7HLR kNyMHu3KOvH6E6lfnWYhwf3RDtmUhPI1fGcrOTv0= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from luklap ([89.247.255.77]) by smtp.web.de (mrweb003 [213.165.67.108]) with ESMTPSA (Nemesis) id 0Lal0y-1iiitl2vWK-00kRhq; Fri, 16 Aug 2019 20:20:09 +0200 Date: Fri, 16 Aug 2019 20:20:07 +0200 From: Lukas Straub To: "Zhang, Chen" Message-ID: <20190816202007.5577756b@luklap> In-Reply-To: <9CFF81C0F6B98A43A459C9EDAD400D780621F1B6@shsmsx102.ccr.corp.intel.com> References: <20190815200815.2cffc21b@luklap> <20190815185737.GC2883@work-vm> <20190815214804.69e4334f@luklap> <9CFF81C0F6B98A43A459C9EDAD400D780621F1B6@shsmsx102.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:CnRsyoIO+p5p335u4c2tF5FAk3MCscL1Qp879B9yn110jEJKX7Q f9hpN//VRK4IJUuv8wOou/ZDlUzAOU1KMg4zmWH5WvAiub2eZryYoEAXNZE9O6iT2jNQ8xq vjb92DW45w5xTCeeCvZU0gY7R9EMH+Fc6s1jsrX5uAqpZkTh7UnsavBhDBEy5rhyfiejsNr 57+dd6Ypv+pRRX45cl4mA== X-UI-Out-Filterresults: notjunk:1;V03:K0:7KIcbYGv3+0=:C7hZXYjHh4viqBwUoYdzE1 D7NE0uQ6h0VIBJWRzEVxs2THpmezwXqO9vNtbHikBDJq0XzLfivprnbQV8+bFzUSD1ErE6aAl ylYzPQeatIm8t7Pf/AZPJt/26lmqwd7xqSGplvNINwyDY+KA90I7RoDxj6h8oZpvwzNwelpBv tlk2pY7tT/D1jX6a8I7GKeOtSirPhA7z101w0niCuFqddE03DU0QphoWGDuWnt1Rins4YanTn Ypb66Unc7p+zKKKk7VEzuNw8ksXOu3AKtCEyCFi8a+ALuzx8IQQ6Heq31bltnCZWKzFgpl2lq +EXA2dY4VWrygzYQVYK+4CqCceXsBOW2xJsndTK3WDhHtVnHMfxx4FW1YN9BFfOTjLjrlIq4J dvhMGTXbKoKZSM1F2H8pl5gdWv4Krl+Ukkb6Kc0jQR2sdRXOPiE4J5sfuf3syldvWeE5rYE+3 NL3mv3SGD2fv/MSmfTdc2bUz7cisTnZS9MkRHHSr6lmR48ceA6FM7gp/hjQVP6fyYEvq6riLu JiJW+69R/Gjpx36mGFXcn5YO43ngOQma/LCE41JYPDQy6xeCl7tPsQXAGZh87pCywkUCNcsxs WGtuQvqAFBxYmKZHwPa4yEdr14zWRyQtXPuDFlReE5UPyMUfZYWeoXzsZFzGDTu18BabLxCEZ hXxhZMA9k/BvVJKq7V3u5SH5vryme9EkXqjzOcZc5GcXsDOcNNBD/NwgTz+v3aFsOG2yEqok1 LjQI301Rfsoi0SBx0AZ1C9/4BhDjP+NdxO5uGeQOu0tcjzsQIxAvDBqmD4wWG6TqhjGVBgp3b i5cDcSL4z99zizdVyf9d+OWblgVAEOE46UUb0r6+TKZoSafChihcE6Vm5xDiB46CxevH4XgCg D39boeEl0p6GDYm9F6N4tO+1N6hia0o6dyznV2kBVeTlpw1LoEz7E1gLUBR6X1hbH/EnmRZnz WFmRJgqnf5PUlpat7Czvh0jqs0Y1ycRLidasRF9t39n1iYrQgWpOoGfxC05K01Dt4rPKrugq8 FfvZR+w7NvyHXi3U/nxDfntlPx/4bvTv21iHi6EU1vptQThh1/7+wPR9S4lx3/vco6QEkRut4 YUkh8XAvV6gFReBpIcwqsfIdUz5RQ+tj1Pi0TzOOA4Wm9e7wK6fTKzkN5XQ2kPw/Wq4q3XnlN EUewPMNzjf0lKPCJcceF4flDut2eAwVXDf1ytoMcaUS9+B3g== X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.15.3 Subject: Re: [Qemu-devel] [PATCH v2 0/3] colo: Add support for continious replication X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wen Congyang , Jason Wang , Xie Changlong , "Dr. David Alan Gilbert" , qemu-devel Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 16 Aug 2019 01:51:20 +0000 "Zhang, Chen" wrote: > > -----Original Message----- > > From: Lukas Straub [mailto:lukasstraub2@web.de] > > Sent: Friday, August 16, 2019 3:48 AM > > To: Dr. David Alan Gilbert > > Cc: qemu-devel ; Zhang, Chen > > ; Jason Wang ; Xie > > Changlong ; Wen Congyang > > > > Subject: Re: [Qemu-devel] [PATCH v2 0/3] colo: Add support for contini= ous > > replication > > > > On Thu, 15 Aug 2019 19:57:37 +0100 > > "Dr. David Alan Gilbert" wrote: > > > > > * Lukas Straub (lukasstraub2@web.de) wrote: > > > > Hello Everyone, > > > > These Patches add support for continious replication to colo. > > > > Please review. > > > > > > > > > OK, for those who haven't followed COLO for so long; 'continuous > > > replication' is when after the first primary fails, you can promote > > > the original secondary to a new primary and start replicating again; > > > > > > i.e. current COLO gives you > > > > > > p<->s > > > > > > s > > > > > > with your patches you can do > > > > > > s becomes p2 > > > p2<->s2 > > > > > > and you're back to being resilient again. > > > > > > Which is great; because that was always an important missing piece. > > > > > > Do you have some test scripts/setup for this - it would be great to > > > automate some testing. > > > > My Plan is to write a Pacemaker Resource Agent[1] for qemu-colo and th= en do > > some long-term testing in my small cluster here. Writing standalone te= sts using > > that Resource Agent should be easy, it just needs to be provided with = the right > > arguments and environment Variables. > > Thanks Dave's explanation. > It looks good for me and I will test this series in my side. > > Another question: Is "Pacemaker Resource Agent[1] " like a heartbeat mo= dule? It's a bit more than that. Pacemaker itself is an Cluster Resource Manager= , you can think of it like sysvinit but for clusters. It controls where in= the cluster Resources run, what state (master/slave) and what to do in ca= se of a Node or Resource failure. Now Resources can be anything like SQL-S= erver, Webserver, VM, etc. and Pacemaker itself doesn't directly control t= hem, that's the Job of the Resource Agents. So a Resource Agent is like an= init-script, but cluster-aware with more actions like start, stop, monito= r, promote (to master) or migrate-to. > I have wrote an internal heartbeat module running on Qemu, it make COLO = can detect fail and trigger failover automatically, no need external APP t= o call the QMP command "x-colo-lost-heartbeat". If you need it, I can send= a RFC version recently. Cool, this should be faster to failover than with Pacemaker. What is the plan with cases like Primary-failover, which need to issue mul= tiple commands? > Thanks > Zhang Chen > > > > Regards, > > Lukas Straub > > > > [1] https://github.com/ClusterLabs/resource-agents/blob/master/doc/dev= -guides/ra-dev-guide.asc#what-is-a-resource-agent