Hadoop WordCount示例

Question

成功创建hadoop环境后，当我要在hadoop中使用0.19.1版运行此wordcount示例时，会出现错误，例如，我该如何解决此问题

11/12/30 06:46:13 INFO mapred.FileInputFormat: Total input paths to process : 1

11/12/30 06:46:14 INFO mapred.JobClient: Running job: job_201112300255_0019

11/12/30 06:46:15 INFO mapred.JobClient:  map 0% reduce 0%

11/12/30 06:46:20 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000003_0, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

11/12/30 06:46:24 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000003_1, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

11/12/30 06:46:28 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000003_2, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

11/12/30 06:46:35 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000002_0, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

11/12/30 06:46:39 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000002_1, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

11/12/30 06:46:44 INFO mapred.JobClient: Task Id : attempt_201112300255_0019_m_000002_2, Status : FAILED

java.io.IOException: Task process exit with nonzero status of 1.
    at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:425)

Exception in thread "main" java.io.IOException: Job failed!
    at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1232)
    at word.count.WordCount.main(WordCount.java:53)

Please help me out to resolve this error.

Answer 1

您使用的hadoop版本有一个管理整个作业的作业跟踪器。并且对于该作业的每个子部分(称为任务)，都有一个任务跟踪器来实际执行该工作。您提供的输出是作业跟踪器输出，其实质是:任务失败。要找出该任务内部到底出了什么问题，您必须查看属于失败任务的日志文件。

您可以通过集群的mapreduce web界面访问这些日志。