HBase
  1. HBase
  2. HBASE-7408

Make compaction to use pread instead of sequential read

    Details

    • Type: Improvement Improvement
    • Status: Resolved
    • Priority: Minor Minor
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
    • Labels:
      None

      Description

      As we discovered lately, HFile compactions use sequential reads to fetch blocks. It cause unwanted streaming of data from HDFS to region servers when there is a cache hit. Lets change to use preads to reduce iops on disks.

        Activity

        Hide
        stack added a comment -

        Resolving as 'unresolved'.

        What is wrong here? Complaint is that sequential reads caused unwarranted i/o but don't we want the HDFS pipelining noted here HBASE-5979 when doing compactions?

        Show
        stack added a comment - Resolving as 'unresolved'. What is wrong here? Complaint is that sequential reads caused unwarranted i/o but don't we want the HDFS pipelining noted here HBASE-5979 when doing compactions?
        Hide
        Elliott Clark added a comment -

        I would guess that this was the issue with long running sequential reads blocking the short preads.

        Show
        Elliott Clark added a comment - I would guess that this was the issue with long running sequential reads blocking the short preads.

          People

          • Assignee:
            Rishit Shroff
            Reporter:
            Rishit Shroff
          • Votes:
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            Watchers:
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            Dates

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              Updated:
              Resolved:

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