Hadoop Map/Reduce
  1. Hadoop Map/Reduce
  2. MAPREDUCE-5042

Reducer unable to fetch for a map task that was recovered

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Blocker Blocker
    • Resolution: Fixed
    • Affects Version/s: 0.23.7, 2.0.4-alpha
    • Fix Version/s: 0.23.7, 2.1.0-beta
    • Component/s: mr-am, security
    • Labels:
      None

      Description

      If an application attempt fails and is relaunched the AM will try to recover previously completed tasks. If a reducer needs to fetch the output of a map task attempt that was recovered then it will fail with a 401 error like this:

      java.io.IOException: Server returned HTTP response code: 401 for URL: http://xx:xx/mapOutput?job=job_1361569180491_21845&reduce=0&map=attempt_1361569180491_21845_m_000016_0
      	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1615)
      	at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:231)
      	at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:156)
      

      Looking at the corresponding NM's logs, we see the shuffle failed due to "Verification of the hashReply failed".

      1. MAPREDUCE-5042.patch
        16 kB
        Jason Lowe
      2. MAPREDUCE-5042.patch
        20 kB
        Jason Lowe
      3. MAPREDUCE-5042.patch
        28 kB
        Jason Lowe
      4. MAPREDUCE-5042.patch
        28 kB
        Jason Lowe

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            • Assignee:
              Jason Lowe
              Reporter:
              Jason Lowe
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              Dates

              • Created:
                Updated:
                Resolved:

                Development