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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Write placement questions: ringIterator() and firstTokenIndex()
Date Tue, 12 Jul 2011 21:52:21 GMT
the intended meaning of "initial" is "use this the first time you
start up; it will be ignored after that, if you use nodetool to move
it around."  Sorry for the confusion.

On Tue, Jul 12, 2011 at 12:53 PM, Eric tamme <etamme@gmail.com> wrote:
> On Tue, Jul 12, 2011 at 3:32 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
>> You're going to be mad at how simple the answer turns out to be. :)
>>
>> Nodes "own" the range from (previous, token], NOT from [token, next).
>> So, the last node will get from (50, 75] and the first will get from
>> (75, 0].
>>
>
> Okay i figured it must have been some thing like that, I half expected
> as much.    So ... following the same example .. writing a token of
> value 1
>
>  int i = Collections.binarySearch([0,25,50,75], 1);
>
> insertion point is 1, so binary search will return (-(1) - 1) =  -2
> which then goes through   (-2+1) * -1 = 1
>
> so 1 is returned to ringIterator as the start token ... makes sense.
>
>
> It's just weird that the documentation refers to them as initialTokens
> ... as if they were the starting point, kind of sets the wrong mental
> precedence.  Maybe i just had a different conceptual picture of how
> things worked internally (shrug)
>
>
> Thanks again,
> Eric
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com

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