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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Get Range Slices is broken on 0.6.4 ??
Date Wed, 25 Aug 2010 13:57:37 GMT
yes.  known bug, fixed in 0.6.5 (CASSANDRA-1145, CASSANDRA-1042)

On Wed, Aug 25, 2010 at 8:53 AM, Moleza Moleza <molezam@gmail.com> wrote:
> HI,
> We just recently tried to use 0.6.4 in our production environment and
> had some serious problem.
> The getRangeSlices functionality is broken.
> We have a cluster of 5 machines.
> We use getRangeSlices to iterate over all of the keys in a cf (2062 keys total).
> We are using OrderPreservingPartitioner.
> We use getRangeSlices with KeyRange using keys (not tokens).
> If we set the requestBlockCount (aka: KeyRange.setCount()) to a number
> greater than 2062 we get all keys in one shot (all is good).
> If we try to fetch the keys in smaller blocks (requestBlockCount=100)
> we get BAD RESULTS.
> We get only 800 unique keys back.
> We start with (startKey="" and endKey="") then, after each iteration,
> we set the startKey=lastMaxKey from the prior iteration (to get
> lastMaxKey we use String.Compare to track the largest one from prior
> iteration [we do this cause we assume keys might come back out of
> order]).
> Our keys are strings (obviously the only option in 0.6) that represent numbers.
> Some Sample keys are: (in correct lexi order)
> -1
> 11113
> 11457
> 6831
> 7035
> 8060
> 8839
> ------
> This code (without any changes) was working correctly under 0.6.3 (we
> got same response from getRangeSlices if using requestBlockCounts of
> 10,000 or 100).
> When we upgraded to 0.6.4 it stopped working.
> We tried the 0.6 branch (built the classes and created a
> cassandra.jar) but it still did not work.
> We reverted back to 0.6.3 and (again, without changing the code) it
> started working again.
> --------
> One thing we learned is that when upgrading to the next version, we
> better run a lot of tests to make sure something is not broken going
> forward.
> --------
> What gives?
> Is this a known bug? I could not find anything in JIRA (only one about
> RandomPartitioner).
> Any Clues?
>



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

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