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From Andre Tavares <andre...@gmail.com>
Subject Re: ColumnFamilyInputFormat - error when column name is UUID
Date Mon, 29 Oct 2012 19:37:16 GMT
Marcelo,

das vezes q tive este problema geralmente era porque o valor UUID sendo
tratado para o cassandra não correspondia a um valor "exato"  em UUID, para
isso utilizava bastante o UUID.randomUUID() (para gerar um UUID valido)
e UUID.fromString("081f4500-047e-401c-8c0b-a41fefd099d7") - este para
transformar uma String em UUID valido.

Como temos 2 keyspaces no cassandra (dmp_input->Astyanax) e (dmp->PlayOrm)
pode acontecer destes frameworks tratarem as chaves UUID de maneira
diferentes (em nossa implementação feita )

portanto acho válido a solução que você encontrou (sorry por não ter
enxergado o probs antes caso, seja este o seu caso ...)

Abs,

André

2012/10/29 Marcelo Elias Del Valle <mvallebr@gmail.com>

> Answering myself: it seems we can't have any non type 1 UUIDs in column
> names. I used the UTF8 comparator and saved my UUIDs as strings, it worked.
>
>
> 2012/10/29 Marcelo Elias Del Valle <mvallebr@gmail.com>
>
>> Hello,
>>
>>     I am using ColumnFamilyInputFormat the same way it's described in
>> this example:
>> https://github.com/apache/cassandra/blob/trunk/examples/hadoop_word_count/src/WordCount.java#L215
>>
>>     I have been able to successfully process data in cassandra by using
>> hadoop. However, as this solution doesn't allow me to filter which data in
>> cassandra I want to filter, I decided to create a query column family to
>> list data I want to process in hadoop. This column family is as follows:
>>
>> row key: YYYYMM
>> column name: UUID - user ID
>> column value: timestamp - last processed date
>>
>>      The problem is, when I run hadoop, I get the exception bellow. Is
>> there any limitation in having UUIDs as column names? I am generating my
>> user IDs with java.util.UUID.randomUUID() for now. I could change the
>> method later, but only type 1 UUIDs are 16 bits longer, isn't it?
>>
>>
>> java.lang.RuntimeException: InvalidRequestException(why:UUIDs must be
>> exactly 16 bytes)
>> at
>> org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.maybeInit(ColumnFamilyRecordReader.java:391)
>>  at
>> org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.computeNext(ColumnFamilyRecordReader.java:397)
>> at
>> org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.computeNext(ColumnFamilyRecordReader.java:323)
>>  at
>> com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
>> at
>> com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
>>  at
>> org.apache.cassandra.hadoop.ColumnFamilyRecordReader.nextKeyValue(ColumnFamilyRecordReader.java:188)
>> at
>> org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:532)
>>  at
>> org.apache.hadoop.mapreduce.MapContext.nextKeyValue(MapContext.java:67)
>> at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
>>  at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
>> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
>>  at
>> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:212)
>> Caused by: InvalidRequestException(why:UUIDs must be exactly 16 bytes)
>>  at
>> org.apache.cassandra.thrift.Cassandra$get_range_slices_result.read(Cassandra.java:12254)
>> at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
>>  at
>> org.apache.cassandra.thrift.Cassandra$Client.recv_get_range_slices(Cassandra.java:683)
>> at
>> org.apache.cassandra.thrift.Cassandra$Client.get_range_slices(Cassandra.java:667)
>>  at
>> org.apache.cassandra.hadoop.ColumnFamilyRecordReader$StaticRowIterator.maybeInit(ColumnFamilyRecordReader.java:356)
>> ... 11 more
>>
>> Best regards,
>> --
>> Marcelo Elias Del Valle
>> http://mvalle.com - @mvallebr
>>
>
>
>
> --
> Marcelo Elias Del Valle
> http://mvalle.com - @mvallebr
>

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