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  1. HBase
  2. HBASE-11226

Document and increase the default value for hbase.hstore.flusher.count

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.99.0, 0.98.2
    • Fix Version/s: 0.99.0, 0.98.3
    • Component/s: regionserver
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      HBASE-6466 add the possibility to have multiple threads for the flusher.
      The default value is 1, but this should be incremented to 2 reasons:

      • I've observed that the flush of a region can be delayed because another is in progress. During a write load, this leads to an increased latency because the memstore size increases and then block the client
      • if, by accident, a flusher hits a slow or bad datanode, all the flush will have to wait until the timeouts expires. With 2 or more flushers and some luck the other regions will be flushed by the second thread.

      Lastly this setting is important enough to be documented in the standard hbase site imho.

      I think it's important enough to go in the .98 branch as well
      There will be an impact: as the flush won't be queued (or less queued) we may have more compactions...

        Attachments

        1. 11226.v1.patch
          2 kB
          Nicolas Liochon

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            • Assignee:
              nkeywal Nicolas Liochon
              Reporter:
              nkeywal Nicolas Liochon
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              Dates

              • Created:
                Updated:
                Resolved: