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  1. MariaDB Server
  2. MDEV-26440

Missing connection id value in I_S.thread_pool_queues

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    Details

    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 10.5.10, 10.5.11, 10.5.12
    • Fix Version/s: 10.5.13, 10.6.5
    • Component/s: Server
    • Labels:
      None

      Description

      As far as I can tell, column I_S.thread_pool_queues.connection_id is supposed to contain ids of connections that are waiting for available worker threads.
      The issue is that I haven't observed any values in this column besides NULL.
      That makes it not quite possible to discern connections that are really sleeping from those that have queued queries.

      Can be reproduced using official docker image.

      MARIADB_VERSION=10.5.12 ./test-in-contaner.sh ./thread-pool-queues.sh > ./result.txt
      

      Result:

      cat result.txt 
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        0 |          NULL |                      18301 |
      |        0 |        1 |        0 |          NULL |                      16621 |
      |        0 |        2 |        0 |          NULL |                      16214 |
      |        0 |        3 |        0 |          NULL |                      15903 |
      |        0 |        4 |        0 |          NULL |                      14968 |
      |        0 |        5 |        0 |          NULL |                      14366 |
      |        0 |        6 |        0 |          NULL |                      12835 |
      |        0 |        7 |        0 |          NULL |                      11526 |
      +----------+----------+----------+---------------+----------------------------+
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        1 |          NULL |                      56000 |
      |        0 |        1 |        1 |          NULL |                      56000 |
      |        0 |        2 |        1 |          NULL |                      56000 |
      |        0 |        3 |        1 |          NULL |                      56000 |
      |        0 |        4 |        1 |          NULL |                      56000 |
      |        0 |        5 |        1 |          NULL |                      56000 |
      +----------+----------+----------+---------------+----------------------------+
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        1 |          NULL |                    1068634 |
      |        0 |        1 |        1 |          NULL |                    1068634 |
      |        0 |        2 |        1 |          NULL |                    1068634 |
      |        0 |        3 |        1 |          NULL |                    1068634 |
      +----------+----------+----------+---------------+----------------------------+
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        0 |          NULL |                    2081406 |
      |        0 |        1 |        0 |          NULL |                    2081406 |
      |        0 |        2 |        0 |          NULL |                    2081406 |
      |        0 |        3 |        1 |          NULL |                     584074 |
      |        0 |        4 |        1 |          NULL |                     584074 |
      |        0 |        5 |        1 |          NULL |                     584074 |
      |        0 |        6 |        1 |          NULL |                     466012 |
      +----------+----------+----------+---------------+----------------------------+
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        0 |          NULL |                    3093475 |
      |        0 |        1 |        0 |          NULL |                    1596143 |
      |        0 |        2 |        0 |          NULL |                    1596143 |
      |        0 |        3 |        0 |          NULL |                    1596143 |
      |        0 |        4 |        0 |          NULL |                    1478081 |
      |        0 |        5 |        1 |          NULL |                     920131 |
      |        0 |        6 |        1 |          NULL |                     460330 |
      +----------+----------+----------+---------------+----------------------------+
      +----------+----------+----------+---------------+----------------------------+
      | GROUP_ID | POSITION | PRIORITY | CONNECTION_ID | QUEUEING_TIME_MICROSECONDS |
      +----------+----------+----------+---------------+----------------------------+
      |        0 |        0 |        0 |          NULL |                    2608249 |
      |        0 |        1 |        0 |          NULL |                    2608249 |
      |        0 |        2 |        0 |          NULL |                    2490187 |
      |        0 |        3 |        0 |          NULL |                    1932237 |
      |        0 |        4 |        0 |          NULL |                    1472436 |
      |        0 |        5 |        1 |          NULL |                     836087 |
      |        0 |        6 |        1 |          NULL |                     345225 |
      +----------+----------+----------+---------------+----------------------------+
      

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              Assignee:
              wlad Vladislav Vaintroub
              Reporter:
              narkq Alex Sladkov
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                Dates

                Created:
                Updated:
                Resolved:

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