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 00CF196E6 for ; Mon, 30 Apr 2012 04:17:52 +0000 (UTC) Received: (qmail 9862 invoked by uid 500); 30 Apr 2012 04:17:49 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 9776 invoked by uid 500); 30 Apr 2012 04:17:49 -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 9751 invoked by uid 99); 30 Apr 2012 04:17:48 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 30 Apr 2012 04:17:48 +0000 X-ASF-Spam-Status: No, hits=3.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS,URI_HEX X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [208.113.200.5] (HELO homiemail-a55.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 30 Apr 2012 04:17:42 +0000 Received: from homiemail-a55.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a55.g.dreamhost.com (Postfix) with ESMTP id E0EF212C0DA for ; Sun, 29 Apr 2012 21:17:19 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=thelastpickle.com; h=from :mime-version:content-type:subject:date:in-reply-to:to :references:message-id; q=dns; s=thelastpickle.com; b=xx3eYPmL7n gc6HFa30d3q6eooOHdG9tLendNVTqiigDZJdHJJ5VtHS6A82JNpn1T01BW6N0Oja 2BpCiZz96oztSh26ALCXK2oaZBYcufCAUgJ3zJtNGM8CXNX2MusOJ5X+hVrjzI9s lviU0nHXP9wV+n3I26tLvJvWonmxe7dPk= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=thelastpickle.com; h=from :mime-version:content-type:subject:date:in-reply-to:to :references:message-id; s=thelastpickle.com; bh=L//quAq7/Oqm4Tk3 CUD8LNWE+58=; b=KXsFNJsgqnT6VmDozYu5l6T6DCHKDVMUhtdoi+xqzj43Rqfq AbreUqVEiteYsllNajYTHQIZym5w+0jUb91iiXxPW/lECTa8MUNcF0QVx5AgZo1Y rRINfXMwgrxcU4rYTmMgf0FCT9sqozc3j5NwxDavBW1LBOq6/TUHX7GEz4I= Received: from [192.168.1.52] (unknown [203.109.195.29]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: aaron@thelastpickle.com) by homiemail-a55.g.dreamhost.com (Postfix) with ESMTPSA id 6D99412C0A9 for ; Sun, 29 Apr 2012 21:17:19 -0700 (PDT) From: aaron morton Mime-Version: 1.0 (Apple Message framework v1257) Content-Type: multipart/alternative; boundary="Apple-Mail=_7857C332-115B-423C-96A1-49F338533B39" Subject: Re: Cassandra backup queston regarding commitlogs Date: Mon, 30 Apr 2012 16:17:31 +1200 In-Reply-To: <1335618246414-7508823.post@n2.nabble.com> To: user@cassandra.apache.org References: <1335618246414-7508823.post@n2.nabble.com> Message-Id: <124E3CF9-A7C8-474B-B152-D492041386C3@thelastpickle.com> X-Mailer: Apple Mail (2.1257) X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Mail=_7857C332-115B-423C-96A1-49F338533B39 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Each mutation is applied to the commit log before being applied to the = memtable. On server start the SSTables are read before replaying the = commit logs. This is part of the crash only software design and happens = for every start. AFAIk there is no facility to snapshot commit log files as they are = closed. The best advice would be to to keep them on a mirror set for = durability.=20 Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 29/04/2012, at 1:04 AM, Roshan wrote: > Hi >=20 > Currently I am taking daily snapshot on my keyspace in production and > already enable the incremental backups as well. >=20 > According to the documentation, the incremental backup option will = create an > hard-link to the backup folder when new sstable is flushed. Snapshot = will > copy all the data/index/etc. files to a new folder. >=20 > *Question:* > What will happen (with enabling the incremental backup) when crash = (due to > any reason) the Cassandra before flushing the data as a SSTable = (inserted > data still in commitlog). In this case how can I backup/restore data? >=20 > Do I need to backup the commitlogs as well and and replay during the = server > start to restore the data in commitlog files? >=20 > Thanks. >=20 >=20 >=20 > -- > View this message in context: = http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Cassandra= -backup-queston-regarding-commitlogs-tp7508823.html > Sent from the cassandra-user@incubator.apache.org mailing list archive = at Nabble.com. --Apple-Mail=_7857C332-115B-423C-96A1-49F338533B39 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Each = mutation is applied to the commit log before being applied to the = memtable. On server start the SSTables are read before replaying the = commit logs. This is part of the crash only software design and happens = for every start.

AFAIk there is no facility to = snapshot commit log files as they are closed. The best advice would be = to to keep them on a mirror set for = durability. 

Cheers

http://www.thelastpickle.com

On 29/04/2012, at 1:04 AM, Roshan wrote:

Hi

Currently I am taking daily snapshot on my = keyspace in production and
already enable the incremental backups as = well.

According to the documentation, the incremental backup = option will create an
hard-link to the backup folder when new sstable = is flushed. Snapshot will
copy all the data/index/etc. files to a new = folder.

*Question:*
What will happen (with enabling the = incremental backup) when crash (due to
any reason) the Cassandra = before flushing the data as a SSTable (inserted
data still in = commitlog). In this case how can I backup/restore data?

Do I need = to backup the commitlogs as well and and replay during the = server
start to restore the data in commitlog = files?

Thanks.



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