Can you check your /etc/hosts to see that all master and slave entries are correct? If you up the logs to DEBUG, you will see where this is failing.
Thanks and Regards, Sonal <https://github.com/sonalgoyal/hiho>Hadoop ETL and Data Integration<https://github.com/sonalgoyal/hiho> Nube Technologies <http://www.nubetech.co> <http://in.linkedin.com/in/sonalgoyal> On Mon, Mar 14, 2011 at 9:41 AM, Yorgo Sun <yorgo...@gmail.com> wrote: > Hi all > > I have a hadoop cluster with a namenode and 3 datanodes, I've installed it > by normal process. everything's fine, but it couldn't run wordcount map > reduce job. Follow are output logs > > > [hadoop@namenode hadoop-0.20.2]$ hadoop jar hadoop-0.20.2-examples.jar > wordcount /user/root/text.log /user/output1 > 11/03/14 12:07:13 INFO input.FileInputFormat: Total input paths to process > : 1 > 11/03/14 12:07:13 INFO mapred.JobClient: Running job: job_201103141205_0001 > 11/03/14 12:07:14 INFO mapred.JobClient: map 0% reduce 0% > 11/03/14 12:07:22 INFO mapred.JobClient: map 100% reduce 0% > 11/03/14 12:07:27 INFO mapred.JobClient: Task Id : > attempt_201103141205_0001_r_000000_0, Status : FAILED > Error: java.lang.NullPointerException > at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:796) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) > > 11/03/14 12:07:33 INFO mapred.JobClient: Task Id : > attempt_201103141205_0001_r_000000_1, Status : FAILED > Error: java.lang.NullPointerException > at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:796) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) > > 11/03/14 12:07:40 INFO mapred.JobClient: Task Id : > attempt_201103141205_0001_r_000000_2, Status : FAILED > Error: java.lang.NullPointerException > at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:796) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683) > at > org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605) > > 11/03/14 12:07:49 INFO mapred.JobClient: Job complete: > job_201103141205_0001 > 11/03/14 12:07:49 INFO mapred.JobClient: Counters: 12 > 11/03/14 12:07:49 INFO mapred.JobClient: Job Counters > 11/03/14 12:07:49 INFO mapred.JobClient: Launched reduce tasks=4 > 11/03/14 12:07:49 INFO mapred.JobClient: Launched map tasks=1 > 11/03/14 12:07:49 INFO mapred.JobClient: Data-local map tasks=1 > 11/03/14 12:07:49 INFO mapred.JobClient: Failed reduce tasks=1 > 11/03/14 12:07:49 INFO mapred.JobClient: FileSystemCounters > 11/03/14 12:07:49 INFO mapred.JobClient: HDFS_BYTES_READ=1366 > 11/03/14 12:07:49 INFO mapred.JobClient: FILE_BYTES_WRITTEN=1868 > 11/03/14 12:07:49 INFO mapred.JobClient: Map-Reduce Framework > 11/03/14 12:07:49 INFO mapred.JobClient: Combine output records=131 > 11/03/14 12:07:49 INFO mapred.JobClient: Map input records=31 > 11/03/14 12:07:49 INFO mapred.JobClient: Spilled Records=131 > 11/03/14 12:07:49 INFO mapred.JobClient: Map output bytes=2055 > 11/03/14 12:07:49 INFO mapred.JobClient: Combine input records=179 > 11/03/14 12:07:49 INFO mapred.JobClient: Map output records=179 > > Is there anyone have this problem too? please help me. thanks a lot. > > -- > 孙绍轩 Yorgo Sun > >
