I am using Hadoop 0.20.2. I just wrote my own map-reduce program based on the
map-reduce tutorial at
http://hadoop.apache.org/common/docs/r0.20.2/mapred_tutorial.html
On Jan 26, 2011, at 10:27 AM, Pedro Costa wrote:
> Hadoop 20.1
>
> On Wed, Jan 26, 2011 at 6:26 PM, Tsz Wo (Nicholas), Sze
> <s29752-hadoopu...@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 <sriha...@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-hadoopu...@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 <psdc1...@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
