Reconsider spinlocks in transaction ID allocation path

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    • Type: Improvement
    • Resolution: Unresolved
    • Priority: Major - P3
    • None
    • Affects Version/s: None
    • Component/s: None
    • Storage Engines
    • StorEng - Refinement Pipeline
    • None

      Summary
      We should re-evaluate the spinlocks added by WT-4571 in _txn_get_snapshot_int. This change results in some worse scaling at high thread levels in some workloads with many readers and writers.

      Motivation
      Our investigation in SERVER-55030 led us to conclude that the main source of contention in workloads with many readers and writers is the spinlock inside _txn_get_snapshot_int. By adding a short sleep in this loop, we were able to demonstrate improved performance for some workloads.

            Assignee:
            [DO NOT USE] Backlog - Storage Engines Team
            Reporter:
            Louis Williams
            Votes:
            41 Vote for this issue
            Watchers:
            33 Start watching this issue

              Created:
              Updated: