How to fix "Task attempt_201104251139_0295_r_000006_0 failed to report status for 600 seconds."

Question

I wrote a mapreduce job to extract some info from a dataset. The dataset is users' rating about movies. The number of users is about 250K and the number of movies is about 300k. The output of map is <user, <movie, rating>*> and <movie,<user,rating>*>. In the reducer, I will process these pairs.

But when I run the job, the mapper completes as expected, but reducer always complain that

Task attempt_* failed to report status for 600 seconds.

I know this is due to failed to update status, so I added a call to context.progress() in my code like this:

int count = 0;
while (values.hasNext()) {
  if (count++ % 100 == 0) {
    context.progress();
  }
  /*other code here*/
}

Unfortunately, this does not help. Still many reduce tasks failed.

Here is the log:

Task attempt_201104251139_0295_r_000014_1 failed to report status for 600 seconds. Killing!
11/05/03 10:09:09 INFO mapred.JobClient: Task Id : attempt_201104251139_0295_r_000012_1, Status : FAILED
Task attempt_201104251139_0295_r_000012_1 failed to report status for 600 seconds. Killing!
11/05/03 10:09:09 INFO mapred.JobClient: Task Id : attempt_201104251139_0295_r_000006_1, Status : FAILED
Task attempt_201104251139_0295_r_000006_1 failed to report status for 600 seconds. Killing!

BTW, the error happened in reduce to copy phase, the log says:

reduce > copy (28 of 31 at 26.69 MB/s) > :Lost task tracker: tracker_hadoop-56:localhost/127.0.0.1:34385

Thanks for the help.

Answer 1

The easiest way will be to set this configuration parameter:

<property>
  <name>mapred.task.timeout</name>
  <value>1800000</value> <!-- 30 minutes -->
</property>

in mapred-site.xml