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  1. Cassandra
  2. CASSANDRA-2494

Quorum reads are not monotonically consistent

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Fix Version/s: 1.0.0
    • Component/s: None
    • Labels:
      None

      Description

      As discussed in this thread,

      http://www.mail-archive.com/user@cassandra.apache.org/msg12421.html

      Quorum reads should be consistent. Assume we have a cluster of 3 nodes (X,Y,Z) and a replication factor of 3. If a write of N is committed to X, but not Y and Z, then a read from X should not return N unless the read is committed to at least two nodes. To ensure this, a read from X should wait for an ack of the read repair write from either Y or Z before returning.

      Are there system tests for cassandra? If so, there should be a test similar to the original post in the email thread. One thread should write 1,2,3... at consistency level ONE. Another thread should read at consistency level QUORUM from a random host, and verify that each read is >= the last read.

        Attachments

        1. 2494.txt
          6 kB
          Jonathan Ellis
        2. 2494-v2.txt
          22 kB
          Jonathan Ellis

          Activity

            People

            • Assignee:
              jbellis Jonathan Ellis
              Reporter:
              sbridges Sean Bridges
              Reviewer:
              Sylvain Lebresne
            • Votes:
              2 Vote for this issue
              Watchers:
              8 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: