Thanks for the info. I ran PiEstimator many many times and never have observed such problem. Nicholas
________________________________ From: Pedro Costa <psdc1...@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-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