Enforce sync lookup receives a single result #5777
Merged
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Issue Addressed
Current stable lookup requests include an internal request counter to differentiate requests. Because each lookup manages retries and streams it must handle interleaved packets from different requests.
PR removed the need for this internal counter, where network context handles streams and uniquely tags each request
However, a bug may break the invariant of 1 request at a time per lookup. If this happens, it will result in undefined behavior.
Proposed Changes
This change is quite strict but ensures that in the case of duplicate requests, we don't mix errors and results from other requests. The hard error is easy to pick up from metrics (in
sync_lookups_dropped_total{reason = "BadState"}
) and logs.