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  1. Core Server
  2. SERVER-39616

Fix size of data structure for storing optimes/lock acquisitions/number of operations

    • Type: Icon: Task Task
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 4.1.11
    • Affects Version/s: None
    • Component/s: None
    • None
    • Fully Compatible
    • Storage NYC 2019-03-25, Storage NYC 2019-04-08, Storage NYC 2019-04-22, Storage NYC 2019-05-06

      The ticket admission flow control POC makes use of a data structure that stores samples of the total number of operations applied since startup and the total number of IX lock acquisitions since start up at a point in time corresponding to a specific timestamp.

      It is risky to keep around an in-memory structure that grows in size proportionally to replication lag. This structure should be modified to be of fixed size. For now, the initial fixed size will be ~50 megabytes worth of data, but this size is subject to change and will perhaps be parametrized. Since the oldest entries (entries at the the majority point) are the most valuable information in the structure, it's preferable for the newest samples to lose resolution when the data structure hits its memory limits. Refactor the existing structure to use a deque.

      This approximation does pose the risk of lag not being able to be adequately throttled in certain scenarios.

            Assignee:
            daniel.gottlieb@mongodb.com Daniel Gottlieb (Inactive)
            Reporter:
            maria.vankeulen@mongodb.com Maria van Keulen
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              Created:
              Updated:
              Resolved: