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  1. Hadoop Common
  2. HADOOP-2943

Compression for intermediate map output is broken

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.17.0
    • Fix Version/s: 0.17.0
    • Component/s: None
    • Labels:
      None

      Description

      It looks like SequenceFile::RecordCompressWriter and SequenceFile::BlockCompressWriter weren't updated to use the new serialization added in HADOOP-1986. This causes failures in the merge when mapred.compress.map.output is true and mapred.map.output.compression.type=BLOCK:

      java.io.IOException: File is corrupt!
              at org.apache.hadoop.io.SequenceFile$Reader.readBlock(SequenceFile.java:1656)
              at org.apache.hadoop.io.SequenceFile$Reader.nextRawKey(SequenceFile.java:1969)
              at org.apache.hadoop.io.SequenceFile$Sorter$SegmentDescriptor.nextRawKey(SequenceFile.java:2985)
              at org.apache.hadoop.io.SequenceFile$Sorter$MergeQueue.merge(SequenceFile.java:2785)
              at org.apache.hadoop.io.SequenceFile$Sorter.merge(SequenceFile.java:2494)
              at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.mergeParts(MapTask.java:654)
              at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:740)
              at org.apache.hadoop.mapred.MapTask.run(MapTask.java:212)
              at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:2077)
      

      mapred.map.output.compression.type=RECORD works for Writables, but should be updated.

        Attachments

        1. 2943.patch
          3 kB
          Chris Douglas
        2. 2943.patch
          4 kB
          Chris Douglas
        3. 2943.patch
          6 kB
          Chris Douglas
        4. 2943.patch
          6 kB
          Chris Douglas

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              • Assignee:
                chris.douglas Chris Douglas
                Reporter:
                chris.douglas Chris Douglas
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                Dates

                • Created:
                  Updated:
                  Resolved: