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From "Matthias L. Jugel" <...@thinkberg.com>
Subject token distribution question
Date Sat, 18 Sep 2010 13:53:36 GMT
Hi,

in our setup we have four nodes and we are using the OPP. After starting and writing to the
cluster it starts to get unbalanced as one expects. I would like to do some manual reassignment
as we have some information on how the distribution looks like.

Ben Black's little script seems to do calculate an even distribution considering one uses
RP, am I right?

To get a bit more precise, I need those keys to balance:

- a UUID that looks like "TIMESTAMP-SEQUENTIALID"

The UUID distributes uneven over the years and month as we have only a few sequential ids
early 2009, more later and very many more starting with 2010 and so on. Before I start playing
with load balancing I would like to confirm that it makes sense to take the heuristics and
assign something like this:

node 1: UUID(0,0) -> UUID(2009-12-31, 0)
node 2: UUID(2010-01-01, 0) -> UUID(2010-04-30)
node 3: UUID(2010-05-01, 0) -> UUID(2010-08-31)
node 4: UUID(2010-09-01, 0) -> UUID(MAX, MAX)

and adding new nodes with a new range after last node.

Another question: what influence does the wraparound have in the ring on the partitioning?

Thanks for your help.

Leo.







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