- Writes: a second write to a tag already inside the driver waits in the
queue behind it (_tagsInFlight) while other tags still run under the
cap of 4; queued writes are stamped and failed BadTimeout at dequeue
once older than the 8 s host Ask budget (Props queuedWriteBudget)
instead of being written late.
- Initialise attempts are bounded pessimistically (initializeTimeout,
default 30 s = 2x Tier C) on top of the invoker's token-only timeout:
an overrun is logged as abandoned, reported InitializeFailed so the
retry loop continues, and its late result is dropped by generation.
Generations come from a process-wide Interlocked counter so a prior
incarnation's late result cannot collide (F6).
- PostStop shares one shutdownTimeout budget across shutdown + dispose.
- TelemetryDialSupervisor cancels the establishment deadline on
StreamStopped; FleetDiagnosticsClient builds the ActorSelection inside
the try (a malformed node degrades to "unavailable"); the diagnostics
page labels the column "Last health publish".
- Tests: same-tag serialisation with a distinct-tag positive control;
stale queued write BadTimeout; token-ignoring hung init -> later
attempt connects; stopwatch assertion demoted to a ceiling.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
DriverInstanceDiagnostics.Name carries the string driver-instance id
(what /hosts, telemetry and the artifact key on) and DriverInstanceId
the DB row Guid; the wire record has no slot for the authored display
name. The write-cap test asserts entry order per slot pair instead of
completion order of two concurrent writes.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
DriverHostActor wraps the health publisher it hands its children in a
ChildHealthLedger (last snapshot per driver id, forwarded to the real
publisher), so GetDiagnostics now answers with each child's row id,
authored name, last-published state, device counts (host statuses when
the driver probes hosts, else one device) and last-change time — instead
of Guid.Empty / "Spawned" / 0 / now. Entries are forgotten on StopChild
and operator Restart.
IFleetDiagnosticsClient gains its first consumer: the new
/fleet/diagnostics page (node selector + ?node= query, revision,
running-from-cache notice, per-driver table). FleetDiagnosticsClient
logs the degrade-to-empty path at Warning.
Review ref: 02/U1.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
CallTimeoutSeconds was bound, defaulted and documented but consumed
nowhere. TelemetryDialSupervisor now arms a per-generation deadline on
every dial: a dial that has delivered no event by the deadline is
cancelled and treated as a transport failure (reconnect with a failure
streak). A live node replays its snapshots on subscribe, so this bites
only a dial that never connects (a black-holed host, where the socket
connect has no timeout). An established stream is deliberately not
bounded — the wire has no heartbeat, keepalive pings own its liveness.
Review ref: 02/U2.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- DriverHostActor.StopChild removes the driver's _lastReprovisionUtc stamp
(and its deferred-reprovision timer): the map grew per removed id and a
re-added driver inherited a backoff it never earned (02/L2).
- Stale now registers explicit drops for AttributeValueBatchPublished,
AttributeAlarmPublished, ArtifactForApply and ApplyWedged instead of
letting them hit Unhandled (02/H5).
- DbHealthProbeActor runs its SELECT on the thread pool and pipes the
outcome back (single-flight), with a 2 s command timeout on relational
providers, so a hung SQL Server no longer pins the actor thread and the
cached GetStatus answer stays reachable (02/P7).
- TelemetryLocalHub eviction tombstones are timestamped and swept past a
10 min TTL on the next Evict; a TimeProvider ctor is the test seam (02/L4).
- Tests: ValuePublishes.Single helper replaces the per-value
AttributeValuePublished in CalculationDependencyFlowTests (02/U4, test
half; the production receive is owned by Lane E).
- R05/8 audit: PollGroupEngine.Unsubscribe has no production caller; every
driver already uses UnsubscribeAsync (no change).
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
WriteAttribute was a ReceiveAsync, suspending the child's mailbox for the
whole device round-trip (up to 5 s): writes serialised, the second of two
operator writes to a slow device missed the host's 8 s Ask and was
reverted although the device took it, and every data change queued behind
the write. Writes are now a synchronous Receive that launches the device
call on the thread pool (sender captured, reply from the task, slot freed
by a self-sent WriteCompleted) under a per-driver cap (default 4; excess
writes queue in order). Queued writes fail fast on every exit from
Connected. Subscribe/unsubscribe stay ReceiveAsync.
Review ref: 02/P2.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The Reconnecting retry timer started a new ShutdownAsync + InitializeAsync
pair on every tick whether or not the previous attempt had finished; the
generation token only discarded the older RESULT, so with an Initialize
bound longer than the cadence the teardown ran underneath an attempt still
inside the driver (the dispose-before-overwrite race). An _initInFlight
gate, cleared by the piped InitializeSucceeded/Failed, skips a tick while
an attempt is running; the pre-reconnect teardown is bounded by the
shutdown timeout; PostStop cancels an in-flight attempt before shutting
the driver down.
Review ref: 02/H2.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
DriverInstanceActor.PostStop now bounds IDriver.ShutdownAsync by a
shutdownTimeout (default 5 s, logged on overrun) and then disposes the
driver (IAsyncDisposable preferred, else IDisposable) — but only on a
real stop. PreRestart flags the restart so the PostStop it triggers
skips the dispose, because a supervision restart re-uses the same
driver object (Props closure) and the host re-initialises it.
DiscoveryDriverBrowser disposes its throwaway capture/probe driver
after the bounded shutdown, including after a failed or timed-out one.
Review refs: 02/L1, 02/P4, 06/G-1 (host context), 07/L2.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Keeps the root CLAUDE.md lean by lazy-loading per-area detail (drivers, topology,
data-plane auth, alarms, historian) only when matching files are touched.
Clears CommentChecker findings in src/ (3,280 -> 209, the remainder being false
positives like PLC-5/IEEE-754/M0.0) by adding missing summaries/params/returns,
normalising inheritdoc usage, and removing Gitea/review tracking IDs while keeping
the rationale they annotated. Comment-only: comment-stripped sources are identical
to the parent commit.
The #687/F4 crowding re-read doubled its room up to 8 re-reads with no cap, so a pathological single-ms
cluster on a streaming gateway was streamed several times over for one page. The room is now capped at
ServerHistorian:MaxTieClusterOverfetch (plumbed into GatewayHistorianDataSource as maxPreWindowRows,
default 65536); past it, or once a read has already seen more, the read is BadTooManyOperations with
PreWindowRows set.
Item 1: IHistorianDataSource.MaxRawValuesPerRead (Gateway: learned ceiling - 16 = L; 0 elsewhere, guard-tested).
RawPageLimit plans every raw page on top of #692's lookahead: with L > 0 the read (page P + boundary ties k
+ lookahead) is <= L, P = min(N, L - k - 1) (uncapped: L - k - 1); no room => straight to the tie-cluster
over-fetch (never an uncapped or underflowing request). One re-plan + re-read when the read taught a new
limit or was refused for crowding pre-window rows (HistoryReadLimitExceededException.PreWindowRows): the
page shrinks by them. Over-fetch bound min(MaxTieClusterOverfetch, L - 1); slice size never 0.
Review fixes: F1 a window starting at/before the epoch counts AVEVA's synthetic row as pre-window (a
ceiling-truncated read was reported complete); F2 the page path disables ReverseRawReader's own re-run
(cold end-only ceiling 20/N=3000 cost 3,023 reads, now <= 40); F3 crowded look-back re-read around, not
refused; F4 the #687 crowding re-read room at least doubles (up to 8 re-reads), so a cluster of hundreds
just before a resume point no longer fails on a default gateway; a crowding refusal that leaves no room
is BadTooManyOperations, never a tick-by-tick cursor.
Item 2: ServerHistorian:EventReadHorizon (default 00:00:00 = exact, unchanged). When set, every fresh
HistoryReadEvents window's earlier bound is raised to now - horizon (both directions, all backends).
Lossy by design; documented.
Item 3 (native TimeAverage/Total re-check) stays blocked on historiangw#27.
Joseph Doherty
dohertj2