Investigate AI-agent analysis report on the server-selection specification. This ticket tracks findings identified during a systematic review of the spec: missing test coverage, ambiguous normative language, and spec/test inconsistencies.

Missing Tests

• Hedged reads deprecated in MongoDB 8.0: deprecation warning or behavior — no test for the hedge field or its
  deprecation
• socketCheckIntervalMS: idle connection check after interval expiry — pseudocode is defined but not tested
• ServerSelectionTryOnce option: single-threaded drivers MUST support it; multi-threaded MUST NOT — no test for
  the option or its rejection
• Load-balanced topology server selection — deferred to LB spec but server-selection tests don't include LB topology
  at all
• Tag set with empty document ({}) — "a document of zero or more tags" but empty document edge case not tested

Ambiguities

• "Eligible" definition order: Does maxStalenessSeconds filtering happen before or after tag_sets filtering?
  Terminology section is ambiguous; algorithm section clarifies but they should align.
• EWMA statistical claim: "A weighting factor of 0.2 puts ~85% weight on the 9 most recent observations" — this
  claim is not derivable from the formula alone and is not tested.
• Latency window selection among equal servers: Spec says shortest RTT server is "always a possible choice" but
  doesn't specify selection method among servers within the window. Multi-threaded tests use frequency-based
  selection; single-threaded behavior is unspecified.

Inconsistencies

• RTT calculation → latency window: 14 RTT files and 30+ latency window files tested separately, but no end-to-end
  test verifying RTT calculation correctly feeds into latency window filtering.
• Load-balanced topology: Mentioned in spec (line 815) but deferred; server-selection tests don't cover it — drivers
  must rely only on load-balancers spec tests.

Notes

• 147 test files. Extensive RTT and latency window coverage. in_window tests include operation count tracking for
  multi-threaded fairness.
• Hedged reads noted as deprecated (8.0+) but no migration/deprecation path is tested.
• DRIVERS-3075 (Backlog): replace references to mongos localThreshold
  option.
• DRIVERS-2580 (Backlog): support server selection events.