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 64FDE7A8D for ; Wed, 20 Jul 2011 12:00:51 +0000 (UTC) Received: (qmail 3077 invoked by uid 500); 20 Jul 2011 12:00:48 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 2774 invoked by uid 500); 20 Jul 2011 12:00:42 -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 2752 invoked by uid 99); 20 Jul 2011 12:00:41 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Jul 2011 12:00:41 +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 soverton@acunu.com designates 209.85.212.44 as permitted sender) Received: from [209.85.212.44] (HELO mail-vw0-f44.google.com) (209.85.212.44) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 20 Jul 2011 12:00:34 +0000 Received: by vws12 with SMTP id 12so120652vws.31 for ; Wed, 20 Jul 2011 05:00:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acunu.com; s=google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=yTBCSXelWnwaEFwQfTCJMvkHgPQaqdHHXIg4OPclLrY=; b=Q++mL6sYYAI2P8l0j2x8cs85nfCZJSQkgYejwdCrDyIwHq8ovS4MNnkf6IuVxhRYye WNBQdgq6FoMCZHDXzfQ8XSl8yL3fvOIaT+9EjSYP4HIfKohqwpKxxa8taClPvC/inBaB ZzEyMLE/5r76vklSDmiaRR2aaYC2p6dk9D6M0= MIME-Version: 1.0 Received: by 10.220.178.199 with SMTP id bn7mr780064vcb.7.1311163213551; Wed, 20 Jul 2011 05:00:13 -0700 (PDT) Received: by 10.220.201.67 with HTTP; Wed, 20 Jul 2011 05:00:13 -0700 (PDT) In-Reply-To: References: Date: Wed, 20 Jul 2011 13:00:13 +0100 Message-ID: Subject: Re: What is the nodeId for? From: Sam Overton To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=90e6ba53a0aa96186f04a87ef9e5 X-Virus-Checked: Checked by ClamAV on apache.org --90e6ba53a0aa96186f04a87ef9e5 Content-Type: text/plain; charset=ISO-8859-1 The NodeId is used in counter replication. Counters are stored on each replica as a set of "shards," where each shard corresponds to the local count of one of the replicas for that counter, as identified by the NodeId. A NodeId is generated the first time cassandra starts, and might be renewed during cleanup, or if you explicitly tell cassandra to generate a new one by starting it with -D*cassandra*.renew_counter_id Do either of the NodeIds in the CurrentLocal row also appear in the Local row of the NodeIdInfo CF? the Local row is a history of previous NodeIds belonging to this node. If one appears in the history and the other does not, it is probably safe to assume that the old NodeId was not deleted from the CurrentLocal row correctly, and so you could try removing it from there manually. Sam -- Sam Overton Acunu | http://www.acunu.com | @acunu On 20 July 2011 12:25, Boris Yen wrote: > Hi, > > I think we might have screwed our data up. I saw multiple columns inside > record: System.NodeIdInfo.CurrentLocal. It makes our cassandra dead forever. > I was wondering if anyone could tell me what the NodeId is for? so that I > might be able to duplicate this. > > Thanks in advance > Boris > --90e6ba53a0aa96186f04a87ef9e5 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The NodeId is used in counter replication. Counters are stored on each repl= ica as a set of "shards," where each shard corresponds to the loc= al count of one of the replicas for that counter, as identified by the Node= Id.=A0

A NodeId is generated the first time cassandra starts, and m= ight be renewed during cleanup, or if you explicitly tell cassandra to gene= rate a new one by starting it with -Dcassandra.renew_counter_id=

Do either of the NodeI= ds in the CurrentLocal row also appear in the Local row of the NodeIdInfo C= F? the Local row is a history of previous NodeIds belonging to this node. I= f one appears in the history and the other does not, it is probably safe to= assume that the old NodeId was not deleted from the CurrentLocal row corre= ctly, and so you could try removing it from there manually.
Sa= m
--
Sam Overton
Acunu |=A0http://www.acunu.com=A0| @acunu
=
On 20 July 2011 12:25, = Boris Yen <yulin= yen@gmail.com> wrote:
Hi,

I think we might have screwed our data up. I saw mul= tiple columns inside record: System.NodeIdInfo.CurrentLocal. It makes our c= assandra dead forever. I was wondering if anyone could tell me what the Nod= eId is for? so that I might be able to duplicate this.

Thanks in advance
Boris

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