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From Benjamin Black...@b3k.us>
Subject Re: Question about load balancing.
Date Wed, 17 Nov 2010 18:35:28 GMT
Random partitioner distributes keys approximately evenly across the
entire range of the ring (0-2**127-1).  This means that generally a
given section of the range will contain about the same number of keys.
 If you assign tokens equal-size ranges, they will have similar
numbers of keys.  This is why RP and evenly distributed tokens
(manually assigned) results in good balance of load between nodes.

Since OPP does not have this even distribution property over the
entire range (unless your keys do!), greater care must be exercised in
selecting tokens and in managing distribution of load.

http://www.slideshare.net/benjaminblack/cassandra-summit-2010-operations-troubleshooting-intro

b

On Tue, Nov 16, 2010 at 1:56 PM, Brayton Thompson <thompsbp@grnoc.iu.edu> wrote:
> .7 beta 2 here
> I've been reading about load balancing and some sites seem to imply that using the random
partitioner will keeps your nodes fairly well balanced. I am
> using a 3 node cluster. 1 seed and two others with AutoBootstrap on.
>
> Now i have read that autobootstrap can leave your nodes unbalanced, but doesn't that
only effect existing data? So all new data should be distributed evenly from here on out?
>
> This is not what I am experiencing, so I must be wrong. Of the three nodes, one is twice
as big as another and the third has less than 1% of total data. I have inserted roughly 1.5
million rows into a single CF totaling roughly 600 mb's in data. Is this too small to be a
good test?
>
> Thank you for your time.

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