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Subject: Re: Multiple data center nodetool ring output display 0% owns
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From: David Schairer <dschairer@humbaba.net>
In-Reply-To: <1329097355674-7279122.post@n2.nabble.com>
Date: Sun, 12 Feb 2012 18:09:00 -0800
Cc: cassandra-user@incubator.apache.org
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Message-Id: <323DBC99-8519-4E86-B69B-6520D53FA5CF@humbaba.net>
References: <1329097355674-7279122.post@n2.nabble.com>
To: user@cassandra.apache.org

There was a thread on this a couple days ago -- short answer, the 'owns =
%' column is effectively incorrect when you're using multiple DCs.  If =
you had all 3 servers in 1 DC, since server YYY has token 1 and server =
XXX has token 0, then server XXX would truly 'own' 0% (actually, =
1/(2^128) :) ), and depending on your replication factor might have no =
data (if replication were 1). =20

But two data centers is effectively like two rings - since the two nodes =
in DC2 are token-balanced, you'd see even distribution between them, and =
DC1 has only one server, so that would be even as well (assuming you =
replicate to both sites).

--DRS

On Feb 12, 2012, at 5:42 PM, Roshan wrote:

> Hi
>=20
> I have deployed Cassandra 1.0.6 to a 2 data center and one data center =
(DC1)
> having one node and the other data center (DC2) having two nodes. But =
when I
> do a nodetool ring using one IP, the output says 0% owns of DC1 node. =
Please
> see the output below.
>=20
> # sh nodetool -h 10.XXX.XXX.XX ring
> Address         DC          Rack        Status State   Load            =
Owns  =20
> Token                                      =20
>=20
> 85070591730234615865843651857942052864     =20
> XXX.XXX.XXX.XXX DC2         RAC1        Up     Normal  83.89 KB      =20=

> 50.00%  0                                          =20
> YYY.YYY.YY.YYY  DC1         RAC1        Up     Normal  71.4 KB         =
0.00% =20
> 1                                          =20
> ZZ.ZZZ.ZZZ.ZZ   DC2         RAC1        Up     Normal  65.94 KB      =20=

> 50.00%  85070591730234615865843651857942052864=20
>=20
> Could someone explain this behavior.     =20
>=20
> --
> View this message in context: =
http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Multiple-=
data-center-nodetool-ring-output-display-0-owns-tp7279122p7279122.html
> Sent from the cassandra-user@incubator.apache.org mailing list archive =
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