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From Sasha Dolgy <sdo...@gmail.com>
Subject Re: calculating initial_token
Date Mon, 14 Mar 2011 21:59:16 GMT
ah, you know ... i have been reading it wrong.  the output shows a
nice fancy column called "Owns" but i've only ever seen the percentage
... the amount of data or "load" is even ... doh.  thanks for the
reply.  cheers
-sd

On Mon, Mar 14, 2011 at 10:47 PM, Narendra Sharma
<narendra.sharma@gmail.com> wrote:
> On the same page there is a section on Load Balance that talks about python
> script to compute tokens. I believe your question is more about assigning
> new tokens and not compute tokens.
>
> 1. "nodetool loadbalance" will result in recomputation of tokens. It will
> pick tokens based on the load and not the once assigned by you.
> 2. You can either use decommission and bootstrap with new tokens OR Use
> "nodetool move"
>
> Thanks,
> Naren
>
> On Mon, Mar 14, 2011 at 1:18 PM, Sasha Dolgy <sdolgy@gmail.com> wrote:
>>
>> Sorry for being a bit daft ... Wanted a bit of validation or rejection ...
>>
>> If I have a 6 node cluster, replication factor 2 (don't think this is
>> applicable to the token decision) is the following sufficient and
>> correct for determining the tokens:
>>
>> #!/bin/bash
>> for nodes in {0..5};
>> do
>>    echo "$nodes*(2^127/5)" | bc;
>> done
>>
>>
>>
>>
>> Gives me a result of:
>>
>> 0
>> 34028236692093846346337460743176821145
>> 68056473384187692692674921486353642290
>> 102084710076281539039012382229530463435
>> 136112946768375385385349842972707284580
>> 170141183460469231731687303715884105725
>>
>> My ring right now is:
>>
>>
>> 10.0.0.2  Up     Normal  225 KB          40.78%
>> 24053088190195663439419935163232881936
>> 10.0.0.3    Up     Normal  201.21 KB       19.17%
>> 56667357399723182105247119364967854254
>> 10.0.0.4   Up     Normal  213.15 KB       17.61%
>> 86624712919272143003828971968762407027
>> 10.0.0.5   Up     Normal  214.54 KB       11.22%
>> 105714724128406151241468359303513100912
>> 10.0.0.6  Up     Normal  206.39 KB       5.61%
>> 115259729732973155360288052970888447854
>> 10.0.0.7    Up     Normal  247.68 KB       5.61%
>> 124804735337540159479107746638263794797
>>
>> If my new tokens are correct:
>>
>> 1.  cassandra.yaml is updated on each node with new token
>> 2.  node is restarted and a nodetool repair is run, or is a nodetool
>> loadbalance run
>>
>> Thanks in advance ... been staring at
>> http://wiki.apache.org/cassandra/Operations#Token_selection for too
>> long
>>
>> --
>> Sasha Dolgy
>> sasha.dolgy@gmail.com
>
>



-- 
Sasha Dolgy
sasha.dolgy@gmail.com

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