读/写时出错 (Hadoop)

Question

我遵循了这个教程安装hadoop。好吧，如果我使用 \usr\local\hadoop 作为 hadoop.tmp.dir ，一切都会正常。因为我在这个分区中的空间很小，所以我尝试将此值设置为 /NEW_partition/(ext4) 但我总是收到一些 java 错误。我猜这是因为 hadoop 无法写入该分区。我怎样才能让它发挥作用？

：：：：编辑：：：： 完整的执行结果。

hadoop@FreeLnx:/usr/local/hadoop-0.20.203.0$ bin/hadoop jar hadoop-examples-0.20.203.0.jar wordcount /MY_STORAGE/tmp1/gutnb /MY_STORAGE/tmp1/gutnbou


12/02/12 02:56:00 INFO input.FileInputFormat: Total input paths to process : 3

12/02/12 02:56:00 INFO mapred.JobClient: Running job: job_201202120255_0001

12/02/12 02:56:01 INFO mapred.JobClient:  map 0% reduce 0%

12/02/12 02:56:09 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000004_0, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:09 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_0&filter=stdout

12/02/12 02:56:09 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_0&filter=stderr

12/02/12 02:56:15 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000004_1, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:15 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_1&filter=stdout

12/02/12 02:56:15 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_1&filter=stderr

12/02/12 02:56:21 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000004_2, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:21 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_2&filter=stdout

12/02/12 02:56:21 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000004_2&filter=stderr

12/02/12 02:56:33 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000003_0, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:33 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_0&filter=stdout

12/02/12 02:56:33 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_0&filter=stderr

12/02/12 02:56:39 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000003_1, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:39 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_1&filter=stdout

12/02/12 02:56:39 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_1&filter=stderr

12/02/12 02:56:45 INFO mapred.JobClient: Task Id : attempt_201202120255_0001_m_000003_2, Status : FAILED

java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)

Caused by: java.io.IOException: Task process exit with nonzero status of 126.
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)


12/02/12 02:56:45 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_2&filter=stdout

12/02/12 02:56:45 WARN mapred.JobClient: Error reading task outputhttp://FreeLnx:50060/tasklog?plaintext=true&attemptid=attempt_201202120255_0001_m_000003_2&filter=stderr

12/02/12 02:56:51 INFO mapred.JobClient: Job complete: job_201202120255_0001

12/02/12 02:56:51 INFO mapred.JobClient: Counters: 4

12/02/12 02:56:51 INFO mapred.JobClient:   Job Counters 

12/02/12 02:56:51 INFO mapred.JobClient:     SLOTS_MILLIS_MAPS=24115

12/02/12 02:56:51 INFO mapred.JobClient:     Total time spent by all reduces waiting after reserving slots (ms)=0

12/02/12 02:56:51 INFO mapred.JobClient:     Total time spent by all maps waiting after reserving slots (ms)=0

12/02/12 02:56:51 INFO mapred.JobClient:     SLOTS_MILLIS_REDUCES=0

Answer 1

您可能需要检查已配置的mapred.local.dir目录的权限，默认为${hadoop.tmp.dir}/mapred/local。父目录和所有内容必须由运行 TaskTracker 守护程序的用户拥有，以便任务能够在其中有效写入瞬态数据（并执行其他操作）。