An in-flight subscribe launched against adapter generation N can take up to
SeedOverallTimeout (120s) to answer. If the adapter is swapped in that window
(failover, or the row-97 in-place reconfigure), the completion was applied
unconditionally: it stored a dead session's handle under the tag key, so the
LIVE completion for the same tag read as a duplicate and had its working
monitored item released (tag resolved forever, no data); it re-stamped the old
endpoint's seed values with the CURRENT generation, bypassing the stale-data
guard; and a connection-level failure row from the dead adapter knocked the
healthy new connection back into Reconnecting. The alarm twin released the new
live alarm feed the same way.
Both completions now carry the generation AND the adapter instance they ran
against, and both handlers drop a completion whose generation no longer
matches - no handle store, no seed application, no per-tag or connection-level
failure processing, no duplicate-release logic. Handles the dropped completion
did create are released best-effort against the CAPTURED adapter (handles are
adapter-scoped; MxGateway's are plain ints that collide across sessions), and
the existing release sites in both handlers were switched to the message's
adapter for the same reason. The in-flight markers are deliberately left alone
(ReSubscribeAll/ReSubscribeAllAlarms clear them wholesale and may already have
re-registered the tag/source), and the requester gets a failure reply so its
retry timer re-sends.
Tests: DataConnectionStaleCompletionTests - stale handle not stored / live item
not released, release lands on the old adapter only, seed values not delivered,
stale connection-level failure does not re-enter Reconnecting, stale alarm
completion does not release the live feed. All five fail against the unfixed
handlers.
Joseph Doherty