我正在尝试使用Hadoop 2.2.0在Mahout 1.0-SNAPSHOT中运行seqdirectory命令。关于使用命令：
seqdirectory -i input -o output
堆栈跟踪：
Error: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.initNextRecordReader(CombineFileRecordReader.java:164)
at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.<init>(CombineFileRecordReader.java:126)
at org.apache.mahout.text.MultipleTextFileInputFormat.createRecordReader(MultipleTextFileInputFormat.java:43)
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.<init>(MapTask.java:491)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:734)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:339)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.initNextRecordReader(CombineFileRecordReader.java:155)
... 10 more
Caused by: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
at org.apache.mahout.text.WholeFileRecordReader.<init>(WholeFileRecordReader.java:59)
... 15 more
我认为这是Mahout 0.9的一个问题，并在后备箱中解决了。有什么线索可以解决这个问题吗？我想在MapReduce模式下运行它，所以-xm-sequential不是我想要的答案。
Caused by: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
像这样的错误总是意味着你运行的是与编译时不同的版本。在这里，您没有为Hadoop2编译Mahout。如果不进行一些构建更改，它就无法与Hadoop2协同工作。