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From A J <s5a...@gmail.com>
Subject Re: Partitioning
Date Wed, 16 Feb 2011 14:37:37 GMT
Yes, I read the same and it sounded weird.

*"Note that with RackAwareStrategy, succeeding nodes along the ring should
alternate data centers to avoid hot spots. For instance, if you have nodes
A, B, C, and D in increasing Token order, and instead of alternating you
place A and B in DC1, and C and D in DC2, then nodes C and A will have
disproportionately more data on them because they will be the replica
destination for every Token range in the other data center."*



I hope there is a way where the replica of 1st node of DC1 is 1st node of
DC2
replica of 2nd node of DC1 is 2nd node of DC2 and so on....

Also hope there is a way where replica of 1st node of Rack1in DC1 is 1st
node of Rack2DC1
replica of 2nd node of Rack1inDC1 is 2nd node of Rack2DC1 and so on.....

Please advise if this will not be possible.

2011/2/16 Wangpei (Peter) <peter.wangpei@huawei.com>

>  I have same question.
>
> I read the source code of NetworkTopologyStrategy, seems it always put
> replica on the first nodes on the ring of the DC.
>
> If I am misunderstand, It seems those nodes will became hot spot.
>
> Why NetworkTopologyStrategy works that way? is there some alternative can
> avoid this shortcoming?
>
>
>
> Thanks in advance.
>
>
>
> Peter
>
>
>
> *发件人:* Aaron Morton [mailto:aaron@thelastpickle.com]
> *发送时间:* 2011年2月16日 3:56
> *收件人:* user@cassandra.apache.org
> *主题:* Re: Partitioning
>
>
>
> You can using the Network Topology Strategy see
>
>
> http://wiki.apache.org/cassandra/Operations?highlight=(topology)|(network)#Network_topology
>
>
>
> and NetworkTopologyStrategy in the  conf/cassandra.yaml file.
>
>
>
> You can control the number of replicas to each DC.
>
>
>
> Also look at conf/cassandra-topology.properties for information on how to
> tell cassandra about your network topology.
>
>
>
> Aaron
>
>
>
> On 16 Feb, 2011,at 05:10 AM, "RW>N" <s5alye@gmail.com> wrote:
>
>
> Hi,
> I am new to Cassandra and am evaluating it.
>
> Following diagram is how my setup will be: http://bit.ly/gJZlhw
> Here each oval represents one data center. I want to keep N=4. i.e. four
> copies of every Column Family. I want one copy in each data-center. In
> other words, COMPLETE database must be contained in each of the data
> centers.
>
> Question:
> 1. Is this possible ? If so, how do I configure (partitioner, replica etc)
> ?
>
> Thanks
>
> AJ
>
> P.S excuse my multiple posting of the same. I am unable to subscribe for
> some reason.
> --
> View this message in context:
> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Partitioning-tp6028132p6028132.html
> Sent from the cassandra-user@incubator.apache.org mailing list archive at
> Nabble.com.
>
>

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