title: Getting error in apche Pig when running over yarn "org.apache.hadoop.ipc.Client - Retrying connect to server: tasktracker3/10.201.2.169:50000"
body: <p>I am running Apache Pig 0.11.2 with Hadoop 2.2.0.</p>
  
  <p>Most simple jobs that I run in Pig work perfectly fine.</p>
  
  <p>However, whenever I try to use <strong>GROUP BY</strong> on a large dataset, or the <strong>LIMIT</strong> operator, I get these connection errors:</p>
  
  <blockquote>
    <p>2013-12-18 11:21:28,400 [main] INFO  org.apache.hadoop.ipc.Client -
    Retrying connect to server: tasktracker2/10.201.2.145:54957. Already
    tried 0 time(s); retry policy is
    RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1 SECONDS)
    2013-12-18 11:21:29,402 [main] INFO  org.apache.hadoop.ipc.Client -
    Retrying connect to server: tasktracker2/10.201.2.145:54957. Already
    tried 1 time(s); retry policy is
    RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1 SECONDS)
    2013-12-18 11:21:30,403 [main] INFO  org.apache.hadoop.ipc.Client -
    Retrying connect to server: tasktracker2/10.201.2.145:54957. Already
    tried 2 time(s); retry policy is
    RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1 SECONDS)
    2013-12-18 11:21:30,507 [main] INFO 
    org.apache.hadoop.mapred.ClientServiceDelegate - Application state is
    completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job
    history server 2013-12-18 11:21:31,703 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker1/10.201.2.20:49528. Already tried 0 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:32,704 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker1/10.201.2.20:49528. Already tried 1 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:33,705 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker1/10.201.2.20:49528. Already tried 2 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:33,809 [main] INFO 
    org.apache.hadoop.mapred.ClientServiceDelegate - Application state is
    completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job
    history server 2013-12-18 11:21:34,890 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker3/10.201.2.169:50000. Already tried 0 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:35,891 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker3/10.201.2.169:50000. Already tried 1 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:36,893 [main] INFO 
    org.apache.hadoop.ipc.Client - Retrying connect to server:
    tasktracker3/10.201.2.169:50000. Already tried 2 time(s); retry policy
    is RetryUpToMaximumCountWithFixedSleep(maxRetries=3, sleepTime=1
    SECONDS) 2013-12-18 11:21:36,996 [main] INFO 
    org.apache.hadoop.mapred.ClientServiceDelegate - Application state is
    completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job
    history server 2013-12-18 11:21:37,152 [main] INFO 
    org.apache.hadoop.mapred.ClientServiceDelegate - Application state is
    completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job
    history server</p>
  </blockquote>
  
  <p>The strange thing is that after these errors keeping appearing for about minutes, they'll stop, and the correct output shows up at the bottom.</p>
  
  <p>So Hadoop is running fine and computing the proper output. The problem is just these connection errors that keep popping up. and that causing increase in execution time of the script.</p>
  
  <p>One thing that I have noticed is that whenever this error appears, the job had created and ran multiple JAR files during the job. However, after a few minutes of these message popping up, the correct output finally appears.</p>
  
  <p>I have 5 nodes cluster 1 namenode and 4 datanode. All the daemons are running fine.</p>
  
  <p>Any suggestions on how to get rid of these messages?</p>