Uploaded image for project: 'Cassandra'
  1. Cassandra
  2. CASSANDRA-1332

Scan results out of order

    XMLWordPrintableJSON

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Normal
    • Resolution: Fixed
    • Fix Version/s: 0.7 beta 1
    • Component/s: None
    • Labels:
      None
    • Environment:

      CentOS 5, Java 1.6.0, Cassandra trunk as of 28 July 2010

    • Severity:
      Normal

      Description

      After inserting 10 keys ('0', '1', ... '9') and running scan() with start_key='' and count=7, scan() returns the keys ['7', '3', '6', '5', '0', '8', '2']. When I scan() again with start_key='2' and count=7, I get the keys ['2', '1', '9', '4', '7']. Notice that key "7" appears in both result sets, and the relative order of keys "7" and "2" is inconsistent between the two scan results.

      I see the problem when running on a 4-node cluster. When I run on a 1-node cluster, the problem does not occur. So the attached system test always passes, since system tests use a 1-node cluster, so the test doesn't actually demonstrate the problem.

      A standalone Python program that reproduces the problem is at: http://pastebin.com/FwitG4wf

        Attachments

        1. scan_test.patch
          2 kB
          Dave Revell

          Activity

            People

            • Assignee:
              jbellis Jonathan Ellis
              Reporter:
              drevell Dave Revell
              Authors:
              Jonathan Ellis
            • Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: