[HADOOP-2129] distcp between two clusters does not work if it is run on the target cluster

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.16.0
• Fix Version/s: 0.15.2
• Component/s: util

Environment

Nightly build: http://hadoopqa.yst.corp.yahoo.com:8080/hudson/job/Hadoop-LinuxTest/718/
With patches for HADOOP-2033 and HADOOP-2048.

• Assignee: Doug Cutting
• Reporter: Murtaza A. Basrai
• Created: 30/Oct/07 23:40
• Updated: 08/Jan/08 20:45
• Resolved: 27/Nov/07 21:51

Description

I am trying to copy a directory (~100k files, ~500GB) between two clusters A and B (~70 nodes), using a command like:

hadoop distcp -log /logdir hdfs://namenode-of-A:8600/srcdir hdfs://namenode-of-B:8600/targetdir

I tried 4 ways of doing it:

1) Copy from A to B, by running distcp on A
2) Copy from A to B, by running distcp on B
3) Copy from B to A, by running distcp on B
4) Copy from B to A, by running distcp on A

Invocations 1 and 3 succeeded, but 2 and 4 failed.

I got a lot of errors of the type below:

07/10/30 20:52:11 INFO mapred.JobClient: Running job: job_200710180049_0115
07/10/30 20:52:12 INFO mapred.JobClient: map 0% reduce 0%
07/10/30 20:54:41 INFO mapred.JobClient: map 1% reduce 0%
07/10/30 20:56:52 INFO mapred.JobClient: map 2% reduce 0%
07/10/30 20:57:41 INFO mapred.JobClient: Task Id : task_200710180049_0115_m_000184_0, Status : FAILED
java.io.IOException: Some copies could not complete. See log for details.
at org.apache.hadoop.util.CopyFiles$FSCopyFilesMapper.close(CopyFiles.java:407)
at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:53)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:192)
at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:1760)

followed by the job failing:

07/10/30 22:07:41 INFO mapred.JobClient: map 99% reduce 100%
Copy failed: java.io.IOException: Job failed!
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:688)
at org.apache.hadoop.util.CopyFiles.copy(CopyFiles.java:481)
at org.apache.hadoop.util.CopyFiles.run(CopyFiles.java:555)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:54)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:67)
at org.apache.hadoop.util.CopyFiles.main(CopyFiles.java:566)