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From Richard Low <rich...@wentnet.com>
Subject Re: Cassandra 1.2.9 cluster with vnodes is heavily unbalanced.
Date Thu, 19 Sep 2013 14:03:21 GMT
I think what has happened is that Cassandra was started with num_tokens =
1, then shutdown and num_tokens set to 256.  When this happens, the first
time Cassandra chooses a single random token.  Then when restarted it
splits the token into 256 adjacent ranges.

You can see something like this has happened because the tokens for each
node are sequential.

The way to fix it is to, assuming you don't want the data, shutdown your
cluster, wipe the whole data and commitlog directories, then start
Cassandra again.

Richard.


On 19 September 2013 13:16, Suruchi Deodhar <
suruchi.deodhar@generalsentiment.com> wrote:

> Hi Richard,
> This is a brand new cluster which started with num_tokens =256 on first
> boot and chose random tokens. The attached ring status is after data is
> loaded into the cluster for the first time using sdtableloader and remains
> that way even after Cassandra is restarted.
>
> Thanks,
> Suruchi
>
> On Sep 19, 2013, at 3:46, Richard Low <richard@wentnet.com> wrote:
>
> On 19 September 2013 02:06, Jayadev Jayaraman <jdisalive@gmail.com> wrote:
>
>  We use vnodes with num_tokens = 256 ( 256 tokens per node ) . After
>> loading some data with sstableloader , we find that the cluster is heavily
>> imbalanced :
>>
>
> How did you select the tokens?  Is this a brand new cluster which started
> on first boot with num_tokens = 256 and chose random tokens?  Or did you
> start with num_tokens = 1 and then increase it?
>
> Richard.
>
>

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