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  1. WiredTiger
  2. WT-4487

Use more accurate statistics for various running totals

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    Details

    • Type: Improvement
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Backlog
    • Component/s: None
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      Description

      In WT-4438, we determined that any statistics that do not use atomic increment may be inaccurate. For many cases we don't care about a fractional percentage drift.  But in particular when a statistic holds a counter, and the drift can accumulate in one direction, we may care.

      A check of the source tree looking for matches of STAT.*DECR should identify most or all cases where a statistic value represents a resource count.

      For connection-wide statistics counters, we have: 

       lsm_work_queue_switch
       lsm_work_queue_manager
       lsm_work_queue_app
       session_open
       txn_prepare_active

      and for statistics that are per-data source, we have:

       cursor_open_count
       cursor_update_bytes

      We should fix these to use the STAT.*ATOMIC macros, or document that they may accumulate drift.

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              Assignee:
              backlog-server-storage-engines Backlog - Storage Engines Team
              Reporter:
              donald.anderson Donald Anderson
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                Created:
                Updated: