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From "Tsz Wo \(Nicholas\), Sze" <s29752-hadoopu...@yahoo.com>
Subject Re: PiEstimator error - Type mismatch in key from map
Date Wed, 26 Jan 2011 18:14:45 GMT
Thanks for the info.  I ran PiEstimator many many times and never have observed 
such problem.
Nicholas




________________________________
From: Pedro Costa <psdc1978@gmail.com>
To: mapreduce-user@hadoop.apache.org
Sent: Wed, January 26, 2011 10:09:36 AM
Subject: Re: PiEstimator error - Type mismatch in key from map

Yes, I can reproduce it deterministically. But, I also did some
changes to the Hadoop MR code. Most definitely this is the reason. I'm
looking throughly through the code.

I'll say something after I find the problem.

I was just wondering if this error has happened to someone before.
Maybe I could get a hint and try to see what's my problem easily.

Thanks,

On Wed, Jan 26, 2011 at 6:02 PM, Tsz Wo (Nicholas), Sze
<s29752-hadoopuser@yahoo.com> wrote:
> Hi Pedro,
> This is interesting.  Which version of Hadoop are you using?  And where did
> you get the example class files?  Also, are you able to reproduce it
> deterministically?
> Nicholas
>
> ________________________________
> From: Pedro Costa <psdc1978@gmail.com>
> To: mapreduce-user@hadoop.apache.org
> Sent: Wed, January 26, 2011 5:47:01 AM
> Subject: PiEstimator error - Type mismatch in key from map
>
> Hi,
>
> I run the PI example of hadoop, and I've got the following error:
>
> [code]
> java.io.IOException: Type mismatch in key from map: expected
> org.apache.hadoop.io.BooleanWritable, recieved
> org.apache.hadoop.io.LongWritable
>     at
> org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:885)
>     at
> org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:551)
>     at
>org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:81)
>)
>     at org.apache.hadoop.mapreduce.Mapper.map(Mapper.java:124)
>     at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
>     at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:637)
>     at org.apache.hadoop.mapred.MapTask.run(MapTask.java:343)
>     at org.apache.hadoop.mapred.Child.main(Child.java:190)
> [/code]
>
> I've look at the map function of the class "PiEstimator.class" and it seems
> ok.
>
> [code]
> public void map(LongWritable offset,
>         LongWritable size,
>         OutputCollector<BooleanWritable, LongWritable> out,
>         Reporter reporter) throws IOException {}
> [/code]
>
>
> What's wrong with this examples?
>
> Thanks,
> --
> Pedro
>



-- 
Pedro

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