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Posted to user@cassandra.apache.org by Jonathan Ellis <jb...@gmail.com> on 2010/05/01 06:01:49 UTC
Re: Single Split ColumnFamilyRecordReader returns duplicate rows
Can you create a ticket?
On Fri, Apr 30, 2010 at 4:55 PM, Joost Ouwerkerk <jo...@openplaces.org> wrote:
> There's a bug in ColumnFamilyRecordReader that appears when processing
> a single split. When the start and end tokens of the split are equal,
> duplicate rows can be returned.
>
> Example with 5 rows:
> token (start and end) = 53193025635115934196771903670925341736
>
> Tokens returned by first get_range_slices iteration:
> 16955237001963240173058271559858726497
> 40670782773005619916245995581909898190
> 99079589977253916124855502156832923443
> 144992942750327304334463589818972416113
> 166860289390734216023086131251507064403
>
> Tokens returned by next iteration (first token is last token from
> previous, end token is unchanged)
> 16955237001963240173058271559858726497
> 40670782773005619916245995581909898190
>
> Tokens returned by final iteration (first token is last token from
> previous, end token is unchanged)
> [] (empty)
>
> In this example, the mapper has processed 7 rows in total, 2 of which
> were duplicates.
>
> Joost.
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
Re: Single Split ColumnFamilyRecordReader returns duplicate rows
Posted by Joost Ouwerkerk <jo...@openplaces.org>.
Created CASSANDRA-1042.
On Sat, May 1, 2010 at 12:01 AM, Jonathan Ellis <jb...@gmail.com> wrote:
> Can you create a ticket?
>
> On Fri, Apr 30, 2010 at 4:55 PM, Joost Ouwerkerk <jo...@openplaces.org> wrote:
>> There's a bug in ColumnFamilyRecordReader that appears when processing
>> a single split. When the start and end tokens of the split are equal,
>> duplicate rows can be returned.
>>
>> Example with 5 rows:
>> token (start and end) = 53193025635115934196771903670925341736
>>
>> Tokens returned by first get_range_slices iteration:
>> 16955237001963240173058271559858726497
>> 40670782773005619916245995581909898190
>> 99079589977253916124855502156832923443
>> 144992942750327304334463589818972416113
>> 166860289390734216023086131251507064403
>>
>> Tokens returned by next iteration (first token is last token from
>> previous, end token is unchanged)
>> 16955237001963240173058271559858726497
>> 40670782773005619916245995581909898190
>>
>> Tokens returned by final iteration (first token is last token from
>> previous, end token is unchanged)
>> [] (empty)
>>
>> In this example, the mapper has processed 7 rows in total, 2 of which
>> were duplicates.
>>
>> Joost.
>>
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com
>