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  1. MariaDB ColumnStore
  2. MCOL-1758

TupleJoiner allocates too much RAM

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    Details

    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 1.4.1
    • Component/s: None
    • Labels:
      None
    • Sprint:
      2019-06

      Description

      Every TupleJoiner thread pre-allocates 64MB using our STLPoolAllocator class. With our thread pool that can spawn many threads very quickly pre-allocating a lot of memory. In some systems this will easily blow the configured overcommit. In my tests running 20 simple simultaneous queries it hit 32GB of allocation with only about 1% of that actually used.

      Our STLPoolAllocator class also isn't a pool (it isn't even thread safe so it can't be). We would be likely better off using boost::pool_allocator or another off-the-shelf singleton pool allocator.

        Attachments

        1. 1.2.5-1.pdf
          19 kB
        2. 1.4.1-1.pdf
          25 kB
        3. stack.pdf
          17 kB

          Activity

            People

            Assignee:
            dleeyh Daniel Lee
            Reporter:
            LinuxJedi Andrew Hutchings
            Votes:
            1 Vote for this issue
            Watchers:
            4 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved: