Details

    • Type: Bug
    • Status: Closed
    • Priority: Blocker
    • Resolution: Fixed
    • Affects Version/s: 0.23.0
    • Fix Version/s: 0.23.0
    • Component/s: mrv2, task
    • Labels:
      None

      Description

      In a gridmix run with ~1000 jobs, one job is getting stuck because of 2-3 hanging reducers. All of the them are stuck after downloading all map outputs and have the following thread dump.

      "EventFetcher for fetching Map Completion Events" daemon prio=10 tid=0xa325fc00 nid=0x1ca4 waiting on condition [0xa315c000]
         java.lang.Thread.State: TIMED_WAITING (sleeping)
              at java.lang.Thread.sleep(Native Method)
              at org.apache.hadoop.mapreduce.task.reduce.EventFetcher.run(EventFetcher.java:71)
      
      "main" prio=10 tid=0x080ed400 nid=0x1c71 in Object.wait() [0xf73a2000]
         java.lang.Thread.State: WAITING (on object monitor)
              at java.lang.Object.wait(Native Method)
              - waiting on <0xa94b23d8> (a org.apache.hadoop.mapreduce.task.reduce.EventFetcher)
              at java.lang.Thread.join(Thread.java:1143)
              - locked <0xa94b23d8> (a org.apache.hadoop.mapreduce.task.reduce.EventFetcher)
              at java.lang.Thread.join(Thread.java:1196)
              at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:135)
              at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:367)
              at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:147)
              at java.security.AccessController.doPrivileged(Native Method)
              at javax.security.auth.Subject.doAs(Subject.java:396)
              at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1135)
              at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:142)
      

      Thanks to Karam Singh for helping track this down.

        Attachments

        1. MAPREDUCE-3226-20111020.txt
          3 kB
          Vinod Kumar Vavilapalli

          Activity

            People

            • Assignee:
              vinodkv Vinod Kumar Vavilapalli
              Reporter:
              vinodkv Vinod Kumar Vavilapalli
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              Dates

              • Created:
                Updated:
                Resolved: