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  1. Cassandra
  2. CASSANDRA-1042

ColumnFamilyRecordReader returns duplicate rows

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Fix Version/s: 0.6.5
    • Component/s: None
    • Labels:

      Description

      There's a bug in ColumnFamilyRecordReader that appears when processing a single split (which happens in most tests that have small number of rows), and potentially in other cases. When the start and end tokens of the split are equal, duplicate rows can be returned.

      Example with 5 rows:
      token (start and end) = 53193025635115934196771903670925341736

      Tokens returned by first get_range_slices iteration (all 5 rows):
      16955237001963240173058271559858726497
      40670782773005619916245995581909898190
      99079589977253916124855502156832923443
      144992942750327304334463589818972416113
      166860289390734216023086131251507064403

      Tokens returned by next iteration (first token is last token from
      previous, end token is unchanged)
      16955237001963240173058271559858726497
      40670782773005619916245995581909898190

      Tokens returned by final iteration (first token is last token from
      previous, end token is unchanged)
      [] (empty)

      In this example, the mapper has processed 7 rows in total, 2 of which
      were duplicates.

        Attachments

        1. 1042-0_6.txt
          3 kB
          Jeremy Hanna
        2. 1042-test.txt
          5 kB
          Jonathan Ellis
        3. 1042-v2.txt
          8 kB
          Jonathan Ellis
        4. cassandra.tar.gz
          3 kB
          Jeremy Hanna
        5. Cassandra-1042-0_6-branch.patch.txt
          2 kB
          Jeremy Hanna
        6. CASSANDRA-1042-trunk.patch.txt
          5 kB
          Jeremy Hanna
        7. duplicate_keys.rtf
          0.8 kB
          Jeremy Hanna

          Activity

            People

            • Assignee:
              jbellis Jonathan Ellis
              Reporter:
              joosto Joost Ouwerkerk
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              Dates

              • Created:
                Updated:
                Resolved: