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  1. Cassandra
  2. CASSANDRA-6692

AtomicBTreeColumns Improvements

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Details

    • Improvement
    • Status: Resolved
    • Low
    • Resolution: Fixed
    • 2.1 beta2
    • None

    Description

      There are two improvements to make to the BTree code that should help:

      1) It turns out Stack Allocation is more rubbish than we had hoped, and so the fast route actually allocates garbage. It's unlikely this reduces throughput, but the increased young-gen pressure is probably unwelcome. I propose to remove the fast route for now.

      2) It is not uncommon to race to perform an update, so that the new values are actually out-of-date when we come to modify the tree. In this case the update should recognise that the original (portion of) the tree has not been modified, and simply return it, without allocating a new one.

      Attachments

        1. patch.txt
          11 kB
          Benedict Elliott Smith
        2. 6692.fix
          3 kB
          Benedict Elliott Smith
        3. 6692.3.txt
          8 kB
          Benedict Elliott Smith

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            benedict Benedict Elliott Smith
            benedict Benedict Elliott Smith
            Benedict Elliott Smith
            Jonathan Ellis
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            Dates

              Created:
              Updated:
              Resolved: