我搭了三台CentOS7虚拟机，安装好了hadoop-3.0.0和mahout-distirution-0.9。
准备用随机森林算法建立模型。第一步生成好了描述文件（/KDDdes.info）;第二步建立好了模型（/user/hadoop/nsl-forest）;但第三步就会报错。
这是HDFS：
[hadoop@hadoop1 ~]$ hadoop fs -ls /
Found 5 items
-rw-r--r-- 1 hadoop supergroup 3365886 2018-05-02 23:58 /KDDTest+.arff
-rw-r--r-- 1 hadoop supergroup 18742306 2018-05-02 23:40 /KDDTrain+.arff
-rw-r--r-- 1 hadoop supergroup 2795 2018-05-02 23:42 /KDDdes.info
drwx------ - hadoop supergroup 0 2018-04-29 20:05 /tmp
drwxr-xr-x - hadoop supergroup 0 2018-04-29 20:05 /user
这是第三步
[hadoop@hadoop1 ~]$ hadoop jar /opt/mahout-distribution-0.9/mahout-examples-0.9-job.jar org.apache.mahout.classifier.df.mapreduce.TestForest -i /KDDTest+.arff -ds /KDDdes.info -m /user/hadoop/nsl-forest -a -mr -o nsl-prediction
2018-05-03 00:01:28,469 INFO mapreduce.Classifier: Adding the dataset to the DistributedCache
2018-05-03 00:01:28,471 INFO mapreduce.Classifier: Adding the decision forest to the DistributedCache
2018-05-03 00:01:28,475 INFO mapreduce.Classifier: Configuring the job...
2018-05-03 00:01:28,479 INFO mapreduce.Classifier: Running the job...
2018-05-03 00:01:28,568 INFO client.RMProxy: Connecting to ResourceManager at hadoop1/192.168.80.100:8032
2018-05-03 00:01:28,960 INFO mapreduce.JobResourceUploader: Disabling Erasure Coding for path: /tmp/hadoop-yarn/staging/hadoop/.staging/job_1525056498669_0005
2018-05-03 00:01:29,462 INFO input.FileInputFormat: Total input files to process : 1
2018-05-03 00:01:29,968 INFO mapreduce.JobSubmitter: number of splits:1
2018-05-03 00:01:30,080 INFO Configuration.deprecation: yarn.resourcemanager.system-metrics-publisher.enabled is deprecated. Instead, use yarn.system-metrics-publisher.enabled
2018-05-03 00:01:30,685 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1525056498669_0005
2018-05-03 00:01:30,686 INFO mapreduce.JobSubmitter: Executing with tokens: []
2018-05-03 00:01:31,277 INFO conf.Configuration: resource-types.xml not found
2018-05-03 00:01:31,278 INFO resource.ResourceUtils: Unable to find 'resource-types.xml'.
2018-05-03 00:01:31,330 INFO impl.YarnClientImpl: Submitted application application_1525056498669_0005
2018-05-03 00:01:31,358 INFO mapreduce.Job: The url to track the job: http://hadoop1:8088/proxy/application_1525056498669_0005/
2018-05-03 00:01:31,359 INFO mapreduce.Job: Running job: job_1525056498669_0005
2018-05-03 00:01:38,470 INFO mapreduce.Job: Job job_1525056498669_0005 running in uber mode : false
2018-05-03 00:01:38,470 INFO mapreduce.Job: map 0% reduce 0%
2018-05-03 00:01:42,604 INFO mapreduce.Job: Task Id : attempt_1525056498669_0005_m_000000_0, Status : FAILED
Error: java.lang.ArrayIndexOutOfBoundsException: 946827879
at org.apache.mahout.classifier.df.node.Node.read(Node.java:58)
at org.apache.mahout.classifier.df.DecisionForest.readFields(DecisionForest.java:197)
at org.apache.mahout.classifier.df.DecisionForest.read(DecisionForest.java:203)
at org.apache.mahout.classifier.df.DecisionForest.load(DecisionForest.java:225)
at org.apache.mahout.classifier.df.mapreduce.Classifier$CMapper.setup(Classifier.java:209)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:794)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:342)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1962)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168)
2018-05-03 00:01:46,641 INFO mapreduce.Job: Task Id : attempt_1525056498669_0005_m_000000_1, Status : FAILED
Error: java.lang.ArrayIndexOutOfBoundsException: 946827879
at org.apache.mahout.classifier.df.node.Node.read(Node.java:58)
at org.apache.mahout.classifier.df.DecisionForest.readFields(DecisionForest.java:197)
at org.apache.mahout.classifier.df.DecisionForest.read(DecisionForest.java:203)
at org.apache.mahout.classifier.df.DecisionForest.load(DecisionForest.java:225)
at org.apache.mahout.classifier.df.mapreduce.Classifier$CMapper.setup(Classifier.java:209)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:794)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:342)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1962)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168)
2018-05-03 00:01:51,687 INFO mapreduce.Job: Task Id : attempt_1525056498669_0005_m_000000_2, Status : FAILED
Error: java.lang.ArrayIndexOutOfBoundsException: 946827879
at org.apache.mahout.classifier.df.node.Node.read(Node.java:58)
at org.apache.mahout.classifier.df.DecisionForest.readFields(DecisionForest.java:197)
at org.apache.mahout.classifier.df.DecisionForest.read(DecisionForest.java:203)
at org.apache.mahout.classifier.df.DecisionForest.load(DecisionForest.java:225)
at org.apache.mahout.classifier.df.mapreduce.Classifier$CMapper.setup(Classifier.java:209)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:794)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:342)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1962)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168)
2018-05-03 00:01:55,745 INFO mapreduce.Job: map 100% reduce 0%
2018-05-03 00:01:57,766 INFO mapreduce.Job: Job job_1525056498669_0005 failed with state FAILED due to: Task failed task_1525056498669_0005_m_000000
Job failed as tasks failed. failedMaps:1 failedReduces:0 killedMaps:0 killedReduces: 0
2018-05-03 00:01:57,844 INFO mapreduce.Job: Counters: 9
Job Counters
Failed map tasks=4
Launched map tasks=4
Other local map tasks=3
Data-local map tasks=1
Total time spent by all maps in occupied slots (ms)=10027
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=10027
Total vcore-milliseconds taken by all map tasks=10027
Total megabyte-milliseconds taken by all map tasks=10267648
Exception in thread "main" java.lang.IllegalStateException: Job failed!
at org.apache.mahout.classifier.df.mapreduce.Classifier.run(Classifier.java:127)
at org.apache.mahout.classifier.df.mapreduce.TestForest.mapreduce(TestForest.java:188)
at org.apache.mahout.classifier.df.mapreduce.TestForest.testForest(TestForest.java:174)
at org.apache.mahout.classifier.df.mapreduce.TestForest.run(TestForest.java:146)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
at org.apache.mahout.classifier.df.mapreduce.TestForest.main(TestForest.java:315)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:239)
at org.apache.hadoop.util.RunJar.main(RunJar.java:153)
这是什么问题，求助大神！！！
