From user-return-31552-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Thu Jan 31 18:51:15 2013 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 85505E229 for ; Thu, 31 Jan 2013 18:51:15 +0000 (UTC) Received: (qmail 63697 invoked by uid 500); 31 Jan 2013 18:51:12 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 63637 invoked by uid 500); 31 Jan 2013 18:51:12 -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 63628 invoked by uid 99); 31 Jan 2013 18:51:12 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 31 Jan 2013 18:51:12 +0000 X-ASF-Spam-Status: No, hits=2.7 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_REPLYTO_END_DIGIT,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [72.30.239.19] (HELO nm38-vm3.bullet.mail.bf1.yahoo.com) (72.30.239.19) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 31 Jan 2013 18:51:03 +0000 Received: from [98.139.215.141] by nm38.bullet.mail.bf1.yahoo.com with NNFMP; 31 Jan 2013 18:50:40 -0000 Received: from [98.139.212.248] by tm12.bullet.mail.bf1.yahoo.com with NNFMP; 31 Jan 2013 18:50:40 -0000 Received: from [127.0.0.1] by omp1057.mail.bf1.yahoo.com with NNFMP; 31 Jan 2013 18:50:40 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 691487.88123.bm@omp1057.mail.bf1.yahoo.com Received: (qmail 55547 invoked by uid 60001); 31 Jan 2013 18:50:40 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1359658240; bh=vCx/k/rRCyi6PiWubTFimKLXSDqoeI+QA5vJ2AjdOBc=; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=HHMZnI2dncZsRZD9Q9PWC8v6PYV9sBtSdd21sP+nECLOX8TZIebkNNmFtEdwM9Gz3/F054CvXYZOC37Kjr7U2jHqbEo17JWwzsKUHJBgDtTmSWHeQYZ0kNEcg7T4KB1/LJKcE98rUdYiYt44hcQkg75+NrJiePKS3Pih+8gWzUc= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=tiXCp74+wLioAfhCa6NQzMHNs3+DPck7CUuO94ihJDJh9xXupqcGGGexHe9hdkFOCfP+lKygZIcH82xPN7Zej1mdJ5GdrMAu4IaN0VhM9kairgE8DzXytKsF1l6nIXUqHoqOjCbg8of7O1hu5LcSP1+SiQp2KvMMEvr0JKnlFa4=; X-YMail-OSG: yK_VBb4VM1k98l67cksBQMZT3pLPlve8VQgV.BDC2GnlKf7 O2fAdGFf5oTG1.KLNpeJOw8CRv_0wSl1BuMWZHWyFH8JyZ6RdzuoT.37tD9W Jcp_9xrajXC4u3Hdg5AYr4kKgvFJ_QwOuhaoSBJp.sy_A_G_gDJ419vbAz6n 5eh0FNn0UZ_tUltf6.PaBH9EfwJf5LYhdGlU3riWopW7Xh7y9Bif9c_9p63Z 35frScinyez8qYDR45CS2Jlc5YIN8gvMZLda9_KgVl_evUrJovyIvFeEwKZl kYFSlVkVx0JACKxTwG6QV3OivOMliCP5GMydPO1mRZ.0JzSndJ9WsyzdMqku FRpv0S5KHpWumMbV_udBkAVLptu4B38mOYiD8_1SEBLv_Pic_pSeYGCI5BSw mR1cT3d7HdfTuEhVHRbDuj_Q3L7ghxxEW4UY08dlRwfyLBj9Bkbb40e4gE6l o03zrqE3g9x76cYSpVc6GR4VPi5XznrtFGjEocvtb3eRosEfmvw-- Received: from [208.185.20.30] by web160901.mail.bf1.yahoo.com via HTTP; Thu, 31 Jan 2013 10:50:40 PST X-Rocket-MIMEInfo: 001.001,SGksCkFmdGVyIG1lc3NpbmcgYXJvdW5kIHdpdGggbXkgQ2Fzc2FuZHJhIGNsdXN0ZXIgcmVjZW50bHksIEkgdGhpbmsgSSBuZWVkIHNvbWUgYmFzaWMgdW5kZXJzdGFuZGluZyBvbiBob3cgdGhpbmdzIHdvcmsgYmVoaW5kIHNjZW5lIHJlZ2FyZGluZyBkYXRhIHN0cmVhbWluZy4KTGV0J3Mgc2F5IHdlIGhhdmUgdGhyZWUgbm9kZSBjbHVzdGVyIHdpdGggUkYgPSAzLiDCoElmIG5vZGUgMyBmb3Igc29tZSByZWFzb24gZGllcyBhbmQgSSB3YW50IHRvIHJlcGxhY2UgaXQgd2l0aCBhIG5ldyBub2RlIHdpdGggdGgBMAEBAQE- X-Mailer: YahooMailWebService/0.8.131.499 Message-ID: <1359658240.54372.YahooMailNeo@web160901.mail.bf1.yahoo.com> Date: Thu, 31 Jan 2013 10:50:40 -0800 (PST) From: Wei Zhu Reply-To: Wei Zhu Subject: General question regarding bootstrap and nodetool repair To: Cassandr usergroup MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-285128509-1647342777-1359658240=:54372" X-Virus-Checked: Checked by ClamAV on apache.org ---285128509-1647342777-1359658240=:54372 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi,=0AAfter messing around with my Cassandra cluster recently, I think I ne= ed some basic understanding on how things work behind scene regarding data = streaming.=0ALet's say we have three node cluster with RF =3D 3. =A0If node= 3 for some reason dies and I want to replace it with a new node with the s= ame (maybe minus one) range. During the bootstrap, how the data is streamed= ?=0AFrom what I observed, Node 3 has replicates for its primary range on no= de 4, 5. So it streams the data from them and starts to compact them. Also,= node 3 holds replicates for primary range of node 2, so it streams data fr= om node 2 and node 4. Similarly, it holds replicates for node 1. So data st= reamed from node 1 and node 2. So during the bootstaping, it basically gets= the data from all the replicates (2 copies each), so it will require doubl= e the disk space in order to hold the data? Over the time, those SStables w= ill be compacted and redundant will be removed? Is it true?=0A=0Aif we issu= e nodetool repair -pr on node 3, apart from streaming data from node 4, 5 t= o 3. We also see data stream between node 4, 5 since they hold the replicat= es. But I don't see log regarding "merkle tree calculation" on node 4,5. Ju= st wondering how they know what data to stream in order to repair node 4, 5= ?=0A=0AThanks.=0A-Wei=0A ---285128509-1647342777-1359658240=:54372 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi,
After messing around = with my Cassandra cluster recently, I think I need some basic understanding= on how things work behind scene regarding data streaming.
Let's say= we have three node cluster with RF =3D 3.  If node 3 for some reason = dies and I want to replace it with a new node with the same (maybe minus on= e) range. During the bootstrap, how the data is streamed?
From what= I observed, Node 3 has replicates for its primary range on node 4, 5. So i= t streams the data from them and starts to compact them. Also, node 3 holds replicates for primary range of node 2, so it streams data from node 2 and= node 4. Similarly, it holds replicates for node 1. So data streamed from n= ode 1 and node 2. So during the bootstaping, it basically gets the data fro= m all the replicates (2 copies each), so it will require double the disk sp= ace in order to hold the data? Over the time, those SStables will be compac= ted and redundant will be removed? Is it true?

if we issue = nodetool repair -pr on node 3, apart from streaming data from node 4, 5 to = 3. We also see data stream between node 4, 5 since they hold the replicates= . But I don't see log regarding "merkle tree calculation" on node 4,5. Just= wondering how they know what data to stream in order to repair node 4, 5?

Thanks.
-Wei

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