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From Pedro Costa <psdc1...@gmail.com>
Subject Re: PiEstimator error - Type mismatch in key from map
Date Wed, 26 Jan 2011 18:27:07 GMT
Hadoop 20.1

On Wed, Jan 26, 2011 at 6:26 PM, Tsz Wo (Nicholas), Sze
<s29752-hadoopuser@yahoo.com> wrote:
> Hi Srihari,
>
> Same questions to you: Which version of Hadoop are you using?  And where did
> you get the examples?  I guess you were able to reproduce it.  I suspect the
> examples and the Hadoop are in different versions.
>
> Nicholas
>
>
> ________________________________
> From: Srihari Anantha Padmanabhan <sriharia@yahoo-inc.com>
> To: "mapreduce-user@hadoop.apache.org" <mapreduce-user@hadoop.apache.org>
> Sent: Wed, January 26, 2011 10:15:08 AM
> Subject: Re: PiEstimator error - Type mismatch in key from map
>
> I got a similar error before in one of my projects. I had to set the values
> for "mapred.output.key.class" and "mapred.output.value.class".
> That resolved the issue for me.
> Srihari
> On Jan 26, 2011, at 10:09 AM, Pedro Costa wrote:
>
> 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
>
>



-- 
Pedro

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