Hadoop Map/Reduce
  1. Hadoop Map/Reduce
  2. MAPREDUCE-4907

TrackerDistributedCacheManager issues too many getFileStatus calls

    Details

    • Target Version/s:
    • Hadoop Flags:
      Reviewed

      Description

      TrackerDistributedCacheManager issues a number of redundant getFileStatus calls when determining the timestamps and visibilities of files in the distributed cache. 300 distributed cache files deep in the directory structure can hammer HDFS with a couple thousand requests.

      A couple optimizations can reduce this load:
      1. determineTimestamps and determineCacheVisibilities both call getFileStatus on every file. We could cache the results of the former and use them for the latter.
      2. determineCacheVisibilities needs to check that all ancestor directories of each file have execute permissions for everyone. This currently entails a getFileStatus on each ancestor directory for each file. The results of these getFileStatus calls could be cached as well.

      1. MAPREDUCE-4907-trunk-1.patch
        15 kB
        Sandy Ryza
      2. MAPREDUCE-4907-trunk-1.patch
        15 kB
        Sandy Ryza
      3. MAPREDUCE-4907-trunk-1.patch
        15 kB
        Sandy Ryza
      4. MAPREDUCE-4907-trunk.patch
        15 kB
        Sandy Ryza
      5. MAPREDUCE-4907.patch
        16 kB
        Sandy Ryza

        Activity

        Sandy Ryza created issue -
        Sandy Ryza made changes -
        Field Original Value New Value
        Attachment MAPREDUCE-4907.patch [ 12562625 ]
        Sandy Ryza made changes -
        Status Open [ 1 ] Patch Available [ 10002 ]
        Target Version/s 1.2.0 [ 12321661 ]
        Alejandro Abdelnur made changes -
        Issue Type Bug [ 1 ] Improvement [ 4 ]
        Sandy Ryza made changes -
        Attachment MAPREDUCE-4907-trunk.patch [ 12564046 ]
        Sandy Ryza made changes -
        Attachment MAPREDUCE-4907-trunk-1.patch [ 12564053 ]
        Sandy Ryza made changes -
        Attachment MAPREDUCE-4907-trunk-1.patch [ 12564059 ]
        Sandy Ryza made changes -
        Attachment MAPREDUCE-4907-trunk-1.patch [ 12564062 ]
        Alejandro Abdelnur made changes -
        Status Patch Available [ 10002 ] Resolved [ 5 ]
        Hadoop Flags Reviewed [ 10343 ]
        Fix Version/s 1.2.0 [ 12321661 ]
        Fix Version/s 2.0.3-alpha [ 12323275 ]
        Resolution Fixed [ 1 ]
        Thomas Graves made changes -
        Fix Version/s 0.23.7 [ 12323954 ]
        Arun C Murthy made changes -
        Status Resolved [ 5 ] Closed [ 6 ]

          People

          • Assignee:
            Sandy Ryza
            Reporter:
            Sandy Ryza
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            Dates

            • Created:
              Updated:
              Resolved:

              Development