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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: cassandra 1.2.5- virtual nodes (num_token) pros/cons?
Date Tue, 13 Aug 2013 09:15:21 GMT
@Aaron

Streaming from all the physical nodes in the cluster should make repair
faster, for the same reason it makes bootstrap faster. Shouldn't it ?




2013/8/12 Aaron Morton <aaron@thelastpickle.com>

> Aaron - I read about the virtual nodes at
> http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2
>
>
> Thanks, I did not see anything in there about making repair smoother /
> faster.
>
> Cheers
> A
>  -----------------
> Aaron Morton
> Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 10/08/2013, at 11:39 AM, rash aroskar <rashmi.aroskar@gmail.com> wrote:
>
> Aaron - I read about the virtual nodes at
> http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2
>
>
>
>
>
>
>
>
> On Tue, Aug 6, 2013 at 4:49 AM, Richard Low <richard@wentnet.com> wrote:
>
>> On 6 August 2013 08:40, Aaron Morton <aaron@thelastpickle.com> wrote:
>>
>>> The reason for me looking at virtual nodes is because of terrible
>>> experiences we had with 0.8 repairs and as per documentation (an logically)
>>> the virtual nodes seems like it will help repairs being smoother. Is this
>>> true?
>>>
>>> I've not thought too much about how they help repair run smoother, what
>>> was the documentation you read ?
>>>
>>
>> There might be a slight improvement but I haven't observed any.  The
>> difference might be that, because every node shares replicas with every
>> other (with high probability), a single repair operation does the same work
>> on the node it was called on, but the rest is spread out over the cluster,
>> rather than just the RF nodes either side of the repairing node.  This
>> means the post-repair compaction work will take less time and the length of
>> time a node is loaded for during repair is less.
>>
>> However, the other benefits of vnodes are likely to be much more useful.
>>
>> Richard.
>>
>
>
>

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