- m6: a /current read that sees a new Agent instanceId now also publishes the new
process's cursor (generation-checked, captured with the read's session), so a
later subscription does not open at the dead instance's sequence and flicker
through a clear + re-baseline. Pinned in the T-2 test.
- Documented (code + docs/drivers/MTConnect.md): m1 the bounded stale-read window of
a stream stalled without failing; m4 a refused multi-pair PUT's retry may re-send
an already-applied pair (harmless); m5 a non-Agent 200 now reads reachable to the
ping; m8 a refused raised count takes one transient blip before the step-back.
- m10 confirmed: no host key is persisted (DriverHostStatus dropped, #521) - the
redacted HostName only changes an in-memory /hosts key for a query-bearing URI.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Coordinator ruling on F3: a write with no reply (transport failure / deadline)
sets Degraded with the stamp preserved and a type-only LastError, through a new
_writeDegraded flag folded into PublishHealthy. One success writer is shared:
RecordReadAnswered (a /current answer, an Agent refusal, a live-index read)
clears the read AND write degradations; RecordWriteAnswered clears the write
one; neither clears the other path's stream degradation. Tests both directions
(answered write clears it, good read clears it) plus the converse (an answered
write does not clear a failed read); red with each half removed.
m7: a good /current resets the refusal-dedup latch, so a refusal recurring after a
recovery is logged again (tested).
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Health contract: an MTConnectError document (NO_DEVICE, INVALID_REQUEST, ...) is the
Agent answering. The parsers now mark such an InvalidDataException
(MTConnectXml.IsAgentRefusal - the type is sealed, so a Data marker, every other
handler unchanged); ReadAsync reports the batch Bad but does not degrade the read
path, advances LastSuccessfulRead, clears a prior read degradation and warns once
per distinct refusal. An unparseable answer stays a comms fault.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- T-4: every ReadAsync batch fetched and parsed the whole device /current and
built a fresh index even while the /sample pump held a live one. A read is now
answered from the pump's index (read only - the pump stays its single writer)
while the current-generation pump is running, has delivered since it started and
is not degraded; /current stays the fallback, and its per-batch index is built
over a tag map frozen once per binding instead of per call. A served read clears
the read-path degradation a failed /current left.
- T-2: the /current fallback checks the answer's instanceId; a change (an Agent
restart seen by a browse-only driver) drops the cached /probe model and raises
rediscovery once per distinct id, only while the read's session is still installed.
- The pump also acts on no verdict (Degrade / latch) once its session generation
is gone, so an abandoned pump cannot write health over the new session (T-1 follow-through).
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Joseph Doherty