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  1. Accumulo
  2. ACCUMULO-1637

Update HDFS append/sync precondition check for Hadoop 1.2

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: 1.5.0
    • Fix Version/s: 1.5.1, 1.6.0
    • Component/s: tserver
    • Labels:
      None

      Description

      Apache Hadoop 1.2.0 ships with the durable sync enabled by default and the support append option marked as obsolete. Because of this, the check inside of TabletServer, meant to ensure that the HDFS WAL can function properly, incorrectly fails as it doesn't know that dfs.durable.sync is on by default.

      This can be worked around by specifying the old durable sync property in hdfs-site.xml:

      <property>
        <name>dfs.durable.sync</name>
        <value>true</value>
      </property>
      

      I'm not sure how to best way to address the differences between the newer and older versions of Hadoop and their differing append support.

      Thanks to Carlos Mundi for pointing this out on user@a.a.o

      Using this table to track the presence of these variables and their default from hdfs/o/a/h/h/DFSConfigKeys and from the codebase when there is no config parameter for it.

      Version DFSConfigKeys.DFS_SUPPORT_APPEND_KEY DFSConfigKeys.DFS_SUPPORT_APPEND_DEFAULT "dfs.durable.sync" Specific Configuration Required
      0.20.205.0 defined false not present yes
      0.23.x defined true not present no
      1.0.x defined false not present yes
      1.1.X not present absent implicit "true" no
      1.2.X not present absent implicit "true" no
      2.0.x defined true not present no
      2.1.x defined true not present no
      2.2.0 defined true not present no

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            • Assignee:
              elserj Josh Elser
              Reporter:
              elserj Josh Elser
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              • Created:
                Updated:
                Resolved: