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From Pedro Costa <psdc1...@gmail.com>
Subject PiEstimator error - Type mismatch in key from map
Date Wed, 26 Jan 2011 13:47:01 GMT

I run the PI example of hadoop, and I've got the following error:

java.io.IOException: Type mismatch in key from map: expected
org.apache.hadoop.io.BooleanWritable, recieved
	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)

I've look at the map function of the class "PiEstimator.class" and it seems ok.

public void map(LongWritable offset,
		LongWritable size,
		OutputCollector<BooleanWritable, LongWritable> out,
		Reporter reporter) throws IOException {}

What's wrong with this examples?


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