Vinod, There should be some stderr information on the task attempts' userlogs that should help point out why your task launching is failing. It is probably cause of something related to the JVM launch parameters (as defined by mapred.child.java.opts).
If not there, look into the TaskTracker logs instead to see if you can make some sense out of it. We'd be happy to look at it for you add it to your mail as well (paste direct or pastebin link - do not attach a file). On Fri, Sep 30, 2011 at 4:27 AM, Vinod Gupta Tankala <[email protected]> wrote: > I just setup a pseudo-distributed hadoop setup. but when i run the example > task, i get failed child error. I see that this was posted earlier as well > but I didn't see the resolution. > > http://mail-archives.apache.org/mod_mbox/hadoop-common-user/201108.mbox/%[email protected]%3E > > this is happening on a ec2 linux instance. here are the details - > > 11/09/29 22:41:02 INFO mapred.FileInputFormat: Total input paths to process > : 15 > 11/09/29 22:41:04 INFO mapred.JobClient: Running job: job_201109292240_0001 > 11/09/29 22:41:05 INFO mapred.JobClient: map 0% reduce 0% > 11/09/29 22:41:13 INFO mapred.JobClient: Task Id : > attempt_201109292240_0001_m_000016_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 > 127. > at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258) > > 11/09/29 22:41:13 WARN mapred.JobClient: Error reading task > outputhttp://ip-10-32-61-60.ec2.internal:50060/tasklog?plaintext=true&attemptid=attempt_201109292240_0001_m_000016_0&filter=stdout > 11/09/29 22:41:13 WARN mapred.JobClient: Error reading task > outputhttp://ip-10-32-61-60.ec2.internal:50060/tasklog?plaintext=true&attemptid=attempt_201109292240_0001_m_000016_0&filter=stderr > 11/09/29 22:41:19 INFO mapred.JobClient: Task Id : > attempt_201109292240_0001_m_000016_1, Status : FAILED > .... > 11/09/29 22:41:55 INFO mapred.JobClient: Job complete: job_201109292240_0001 > 11/09/29 22:41:55 INFO mapred.JobClient: Counters: 4 > 11/09/29 22:41:55 INFO mapred.JobClient: Job Counters > 11/09/29 22:41:55 INFO mapred.JobClient: SLOTS_MILLIS_MAPS=24566 > 11/09/29 22:41:55 INFO mapred.JobClient: Total time spent by all reduces > waiting after reserving slots (ms)=0 > 11/09/29 22:41:55 INFO mapred.JobClient: Total time spent by all maps > waiting after reserving slots (ms)=0 > 11/09/29 22:41:55 INFO mapred.JobClient: SLOTS_MILLIS_REDUCES=0 > 11/09/29 22:41:55 INFO mapred.JobClient: Job Failed: NA > java.io.IOException: Job failed! > at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1204) > at org.apache.hadoop.examples.Grep.run(Grep.java:69) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) > at org.apache.hadoop.examples.Grep.main(Grep.java:93) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:616) > at > org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68) > at > org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139) > at > org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:64) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:616) > at org.apache.hadoop.util.RunJar.main(RunJar.java:156) > > > thanks > vinod > -- Harsh J
