From user-return-30512-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Fri Dec 7 17:29:06 2012 Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 4B820DC22 for ; Fri, 7 Dec 2012 17:29:06 +0000 (UTC) Received: (qmail 29546 invoked by uid 500); 7 Dec 2012 17:29:03 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 29517 invoked by uid 500); 7 Dec 2012 17:29:03 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 29497 invoked by uid 99); 7 Dec 2012 17:29:03 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 07 Dec 2012 17:29:03 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of tyler@datastax.com designates 209.85.217.172 as permitted sender) Received: from [209.85.217.172] (HELO mail-lb0-f172.google.com) (209.85.217.172) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 07 Dec 2012 17:28:57 +0000 Received: by mail-lb0-f172.google.com with SMTP id y2so664735lbk.31 for ; Fri, 07 Dec 2012 09:28:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:x-gm-message-state; bh=8DbRypmgW26t6t4diSgIACOEe5/M18jq7PvAGyTgtA8=; b=RzY852QTglqTIOHlv2ljXyoAtxwA9Yyd+n5g+daGxBbHOfNY8fjgUcoPcKZCwRkCOV 99v6uVrwjLOl8zzHdDBWa+kB5CwDvFW9j1mamBZIX7JIapcCSwb5GnY3rpO6s7Pf3cAv JteHyDNr9V9z+67+VZGIPENuQ2HEQx2kMUgQ+gtM5ZBWuRZ5K2glfv8OqQZVJDuXjt7z a6aNnz0A05CvjUxdWzPDKIenVvF378x5hypIYAZw75Bn+6EadaRFUCehJ7bCBA8fsiyt S9RKenxItvs4VOdoSWtpfoAS+wTp4kBK6wi63bUaJiE7EBiA3uUL8Zp7cG3+6gSrBB9V Xviw== MIME-Version: 1.0 Received: by 10.112.46.199 with SMTP id x7mr2797248lbm.109.1354901315684; Fri, 07 Dec 2012 09:28:35 -0800 (PST) Received: by 10.112.33.4 with HTTP; Fri, 7 Dec 2012 09:28:35 -0800 (PST) In-Reply-To: References: Date: Fri, 7 Dec 2012 11:28:35 -0600 Message-ID: Subject: Re: how to take consistant snapshot? From: Tyler Hobbs To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=bcaec5540568a0897904d0468b59 X-Gm-Message-State: ALoCoQlxNVTmiorL9L0bSsCRYXJL6jawU6cgVqCtJmk3Q8t27UZuvIYHTF+qlKanABpfKvZDVH7q X-Virus-Checked: Checked by ClamAV on apache.org --bcaec5540568a0897904d0468b59 Content-Type: text/plain; charset=ISO-8859-1 Snapshots trigger a flush first, so data that's currently in the commit log will be covered by the snapshot. On Thu, Dec 6, 2012 at 11:52 PM, Andrey Ilinykh wrote: > > > > On Thu, Dec 6, 2012 at 7:34 PM, aaron morton wrote: > >> For background >> >> >> http://wiki.apache.org/cassandra/Operations?highlight=%28snapshot%29#Consistent_backups >> >> If you it for a single node then yes there is a chance of inconsistency >> across CF's. >> >> If you have mulitple nodes the snashots you take on the later nodes will >> help. If you use CL QUOURM for reads you *may* be ok (cannot work it out >> quickly.). If you use CL ALL for reads you will be ok. Or you can use >> nodetool repair to ensure the data is consistent. >> >> I'm talking about restoring whole cluster, so all nodes are restored from > backup and all of them are inconsistent because they lost data from commit > logs. It doesn't matter what CL I use, some data may be lost. > Cassandra 1.1 supports commit log archiving > http://www.datastax.com/docs/1.1/configuration/commitlog_archiving > I think if I store both flushed sstables and commit logs it should solve > my problem. I'm wondering if someone has any experience with this feature? > > Thank you, > Andrey > -- Tyler Hobbs DataStax --bcaec5540568a0897904d0468b59 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Snapshots trigger a flush first, so data that's currently in the commit= log will be covered by the snapshot.

On Thu, Dec 6, 2012 at 11:52 PM, Andrey Ilinykh= <ailinykh@gmail.com> wrote:



On Thu, Dec 6, 2012 at 7:34 PM, aar= on morton <aaron@thelastpickle.com> wrote:
For background


If you it for a single node then yes there is a chance = of inconsistency across CF's.=A0

If you have m= ulitple nodes the snashots you take on the later nodes will help. If you us= e CL QUOURM for reads you *may* be ok (cannot work it out quickly.). If you= use CL ALL for reads you will be ok. Or you can use nodetool repair to ens= ure the data is consistent.=A0

I'm talking about restorin= g whole cluster, so all nodes are restored from backup and all of them are= =A0inconsistent because they lost data =A0from commit logs. =A0It doesn'= ;t matter what CL I use, some data may be lost.=A0
Cassandra 1.1 supports commit log archiving

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Tyler Hobbs
DataStax
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