Driver.Mqtt.Contracts-004/-005/-006/-007.
-004: retainSeed was the last behavioural key read leniently, so "retainSeed":"false"
— what a CSV import produces — silently became the default TRUE, the INVERSE of the
authored intent. Both mappers now read it through TryReadBoolStrict (the qos
absent/valid/present-but-invalid split) and DescribeRejection names it. The authoring
side needed no hand-mirrored rule: MqttTagConfigModel.Validate already consults this
same parse through TagConfigParseGate, so the save is blocked with the inspector's
wording — pinned by a new AdminUI parity theory pair.
-005: the seven [Range] attributes on MqttDriverOptions/MqttPlainOptions never ran —
the options are bound by JsonSerializer, and nothing in the four MQTT projects calls
Validator.TryValidateObject. Two of them CONTRADICTED the real authority (KeepAlive's
[Range(1,…)] forbade the zero Normalize admits as legal MQTT; MaxPayloadBytes' forbade
the non-positive value its own remarks document as falling back to 1 MiB), so wiring
them up would have broken deliberate behaviour. Deleted, with each property naming
where its bound actually lives. The one escape they papered over is closed: an
out-of-range defaultQos rode into the SUBSCRIBE verbatim, and MqttSubscriptionManager's
constructor now clamps it exactly as the AdminUI driver form already persists.
-006: the DateTime write arm cast a negative long to ulong, so 1969-12-31 published a
timestamp ~584 million years in the future; it is now refused as ValueNotRepresentable.
An Unspecified kind was handed to ToUniversalTime(), which reads it as LOCAL — the same
authored instant encoded differently on the two nodes of a redundant pair; it is now
read as UTC.
-007: Format/FormatState enforced only null/empty, and nothing at all on deviceId, so
the type was not round-trip-closed. They now apply the parser's IsValidSegment (plus
'/', which only the format side can see). MqttWriteEncoder's own guards stay — TryEncode
returns an error rather than throwing, and that contract does not change.
Driver.Mqtt-007 (Low, error handling). OnReconnectedAsync throws when a
re-subscribe is granted zero filters — MqttConnection's contract is that a
throwing Reconnected subscriber tears the fresh session down and retries under
backoff, because a connected-but-deaf driver is the one outcome this path must
never serve. But when the live subscribed topics resolved to zero filters in the
first place it logged a warning and returned, reaching the same "nothing was
re-established" state by a different route and giving it the opposite answer.
Throw there too, and say so in the remarks so the type states ONE rule. It costs
no other tag — every live topic is in the set that resolved to nothing, so there
is nothing left flowing to protect, which is the whole reason the partial-
rejection case is exempt — and it is not permanent: the retry runs against
whatever Register has published by then.
Test reaches the state the only way production can: Register prunes
_subscribedTopics of the topics its new table no longer carries, but a SUBSCRIBE
already in flight records its own topic AFTER that prune ran, so a deploy landing
inside the round-trip leaves a live topic no authored tag resolves to. Paired
with the control that a reconnect with no live subscriptions at all stays a
no-op — throwing there would tear down the session of every driver whose tags
have not been subscribed yet.
Findings from the per-module review of Driver.Mqtt at b990adae
(code-reviews/Driver.Mqtt/findings.md records all ten; these are the fixed
ones).
Driver.Mqtt-001 (High) — MqttSubscriptionManager._subscribedTopics is a claim
about the broker session it established filters on, and AttachTo never cleared
it, but the manager OUTLIVES a session rebuild (AdoptOptions keeps it whenever
the ingest identity is unchanged). After a driver-host reconnect
(ShutdownAsync + InitializeAsync, the #527 watchdog's retry) or a
ReinitializeAsync that only changed the endpoint/credentials, the host's
re-subscribe resolved an empty pending set, sent no SUBSCRIBE at all, and left
the driver Connected/Healthy on a session carrying ZERO subscriptions — no
error, no Bad status, values frozen until the new session happened to drop.
AttachTo now forgets them, mirroring SparkplugIngestor.AttachTo's reset.
Driver.Mqtt-002 (High) — InitializeCoreAsync published _connection and
_primaryHost over whatever the driver already held, so a second initialize
stranded a connected, self-supervising broker session (plus a second Sparkplug
primary-host claim) that no later dispose could reach. Reachable without any
teardown of ours via DriverInstanceActor.AdoptConfigDuringInit. Now tears down
first, under the gate both callers already hold.
Driver.Mqtt-003 (Medium) — connectTimeoutSeconds is [Range]-annotated but
unvalidated on the runtime path; 0 makes every deadline fire immediately and a
negative value throws ArgumentOutOfRangeException out of ShutdownAsync and
DisposeAsync. Normalized once, at the seam every options instance passes.
Also: ShutdownAsync keeps the live last-message instant (-004), three usings
left behind by #512 removed (-005), stale remarks corrected (-009, -010), and
docs/drivers/Mqtt.md now distinguishes the two kinds of reconnect.
Tests 708 -> 713. All three regression tests were confirmed to fail against
the un-fixed code, with two controls that pass in either state.
C1 (CRITICAL). AuthoredTable routed any wildcard-authored tag into `Wildcards`
and never into the concrete topic index. But the two paths that reconstruct
state from a SUBSCRIBED FILTER STRING — OnReconnectedAsync's re-subscribe set
and DegradeTopic — both looked up that concrete-only index, and
`_subscribedTopics` keys on the wildcard PATTERN ("f/+/temp"). So:
- reconnect resolved zero filters for a wildcard tag, hit a silent early
return, and issued NO subscribe. The cache keeps its last Good value, so the
tag never turns Bad — it just stops updating forever behind a connection
reporting healthy. Exactly the silent-death mode MqttConnection's own remarks
warn about, left unguarded for wildcards.
- DegradeTopic missed too, so a SUBACK rejection of a wildcard filter degraded
nothing and left the tag at BadWaitingForInitialData.
Fix: AuthoredTable now carries `ByFilter` (EVERY def, keyed by its authored
topic filter, wildcards included) alongside `ByExactTopic` (concrete only) and
`Wildcards`. Delivery matches an incoming published topic — which never carries
a wildcard — so it keeps using ByExactTopic + the comparer scan. Every path
keyed on a filter string uses ByFilter. The distinction is documented on the
record. The silent early return is now a Warning naming the orphaned topics.
Also in this pass:
- I2: bounded decode on the dispatcher thread. A body over `MaxPayloadBytes`
(default 1 MiB, ctor-settable) is refused BEFORE any GetString/JsonDocument
parse and degrades its own tags. Unbounded decode on the shared dispatcher is
paid by every subscription, not just the offending topic. NOTE: promoting this
to an operator-facing MqttDriverOptions key (+ WithMaximumPacketSize) needs a
.Contracts edit this task is scoped out of; flagged in the XML docs.
- I3: integral-valued reals now coerce to integer tags. JS/Python edge gateways
serialize an integer as 5.0, and TryGetInt32/int.TryParse are syntactic — an
Int32 tag fed by such a gateway silently never received data. Parsed via
decimal so integrality and range are exact across Int64/UInt64. A genuinely
fractional 5.5 is still refused, never rounded.
- I4: the JSON document is parsed ONCE per message and shared across the whole
fan-out (the documented "one document, one JSONPath per signal" shape was
re-parsing per tag). Zero-alloc via a ref struct when no Json tag matches.
- I5: pinned the documented JSON-string-holding-a-number coercion end-to-end.
- Minor: Register now prunes `_subscribedTopics` / `_handleByRawPath` entries for
tags a redeploy dropped, so a deleted topic stops being re-subscribed forever.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
MqttSubscriptionManager is the P1 plain-MQTT ingest path: it holds the authored
RawPath → MqttTagDefinition table behind the shared EquipmentTagRefResolver,
establishes one SUBSCRIBE per distinct authored topic, and turns each inbound
message into a LastValueCache update plus an OnDataChange notification.
Load-bearing choices, each pinned by a falsified test:
- The published reference IS the RawPath (def.Name), never the topic and never
the TagConfig blob — DriverHostActor's dual-namespace fan-out is RawPath-keyed,
so any other key passes every unit test and delivers nothing in production.
- One message fans out to EVERY tag on its topic; several tags routinely share a
topic with different jsonPaths, and stopping at the first match silently starves
the rest.
- An unauthored topic raises nothing: MQTT ingest never auto-provisions.
- Wildcard-authored topics (accepted by the parser, warned at deploy) match via
MQTTnet's own MqttTopicFilterComparer, so '+'/'#' behave as a broker would.
Concrete topics stay a single lookup; the wildcard scan runs only when one exists.
- Retained seeds are honoured natively on MQTT 5.0 (retain handling) AND filtered
client-side on the retain flag, because 3.1.1 brokers always replay.
- Nothing throws on MQTTnet's dispatcher thread: a malformed payload degrades that
tag (BadDecodingError / BadTypeMismatch), and a throwing OnDataChange subscriber
is contained without starving the tags behind it.
- The manager issues the FIRST subscribe itself — Reconnected deliberately does not
fire after the initial ConnectAsync.
- Reconnect re-subscribe: total failure THROWS (MqttConnection then tears the
session down and retries under backoff, rather than serving a connected-but-deaf
driver); a partial SUBACK rejection degrades only the denied refs, because
retrying forever over one ACL-denied topic would take every tag dark.
MqttConnection gains a MessageReceived observer (fired on the dispatcher, throwing
observers contained) and a bounded SubscribeAsync under its own linked-CTS deadline
— deliberately not MqttClientOptions.Timeout, which already governs every MQTTnet
op. A refused filter is an outcome, not an exception; only the SUBSCRIBE itself
failing throws. Classify() is parameterised by operation name (messages unchanged
for connect).
JSONPath is a documented subset ($, $.a.b, $['a'], $.a[0]); filters/slices/
recursive descent report a miss rather than pulling in a JSONPath package for an
expression form that selects a set where a tag needs one scalar.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty