C1 (critical): B6 computes the plan off the pinned thread while B1 made writes
non-creating, so a value/status/alarm write for a node the in-flight plan adds
was skipped, and change-driven drivers never republish it (BadWaitingForInitialData
indefinitely; on a full rebuild every re-subscribe value landed on discarded
nodes). OpcUaPublishActor now applies writes immediately AND remembers the
latest per (realm, id) while a plan is in flight or queued (value+status
compose; alarm state/quality coalesce to the latest, which the node's delta
gate makes inert on an existing condition), replays it after each apply before
answering, and drops it once the pipeline is idle. Bounded (250k keys by
default; beyond it new keys are not held, logged once).
I2: the data-plane-authority parse runs in its own try inside the plan task; a
throw is logged and never degrades the address-space apply.
I3: the SDK's DeleteMonitoredItems releases an item's component-cache
reference on a Good delete; a tombstoned item's reference was already
released, so the delete took one from the re-created node's entry. Released
items are remembered and the orphan delete takes one back first. Event items
never held a reference (EventManager + SubscribeToEvents), so the three
event-item releases are gone.
I4: direct tests for the HistoryUpdate override's per-request updater check
and the HistoryReadEvents override's source guard (both reached by restoring
the bit after a reset - the B7 race window); fixed the false remark.
Minors: the MaterialiseAlarmCondition kind-swap tombstones the dropped
instance; a bytes-less rebuild arriving mid-plan queues behind it (replies in
order); a PlanReady/PlanFailed from a previous actor incarnation is ignored and
its requester answered degraded; the tie-cluster end bound of an uncapped read
fits against the backend ceiling (defence in depth - guarded by a sweep test);
the lock-time benchmark stays in the default run, headroom noted.
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The fixture wedged EVERY write on one shared token-ignoring release gate, so
the later same-tag write was also hung, and the 300 ms pessimistic bound
abandoned it while the test was still polling before ReleaseWrites(). Its
reason was "write did not complete within" (the bound), not "queued for" (the
queue budget), and it had already entered the driver, so the tag had been
released. The release path is correct. Only the first write now hangs, and
later writes complete at once.
The abandon reason formatted the bound with TotalSeconds:F0, which printed a
300 ms bound as "0s". It now uses milliseconds, and the test asserts it.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
B6 moved the address-space-rebuild span into ApplyPlan, so the two rebuilds
that complete synchronously on the actor thread (no applier -> raw-sink
rebuild; no artifact bytes -> held) stopped emitting it
(OtOpcUaTelemetryHookTests.RebuildAddressSpace_starts_an_address_space_rebuild_span).
Both now open their own span.
B7 (late HistorianDataSource / HistorianDataUpdater re-evaluate the
capability bits) reversed three tests that pinned the old "fixed at
materialisation" contract. Re-expressed against the new one, end to end:
- events: a folder promoted without a source is unsupported, then served
once a source is wired (source reached);
- in-process HistoryUpdate: clearing the updater retracts HistoryWrite and
the old updater is never reached;
- over the wire: a late updater lights HistoryWrite and an insert reaches
it; a reset retracts the bit and the insert is BadHistoryOperationUnsupported.
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Lane H1 follow-through: SyncAdvertisedAggregates now also calls
HistoryPaging.AdvertiseMaxReturnDataValues(Server, source
.MaxRawValuesPerRead) so HistoryServerCapabilities/MaxReturnDataValues
(i=11273) follows the historian source on every assignment (the Null
default advertises 0 = no limit); a false return logs a Warning (the cap
is enforced by HistoryRead regardless).
Test: NodeManagerMaxReturnDataValuesSyncTests reads i=11273 back through
the SDK master node manager after setting a capped source (7000, 250)
and after resetting to the Null source (0).
Refs #732#736
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
H1 fuzz finding (routed to Lane B because AppendEndBoundAsync lives in
OtOpcUaNodeManager.cs): a bounded HistoryRead-Raw page sized BELOW
NumValuesPerNode by the backend's row ceiling (RawPageLimit.Plan) took
the end bound whenever its data fitted, because the fit was judged
against NumValuesPerNode instead of the page's effective cap — a full
ceiling-sized page came back with cap + 1 values. The bound is now
fitted against the page allowance (the ceiling-adjusted data cap plus
the start bound a first page already carries); when the page is full
the bound goes to the next page through the continuation point.
Test: NodeManagerHistoryReadBoundsTests
.A_full_ceiling_sized_page_carries_the_end_bound_on_the_next_page
(ceiling 4 ⇒ 3 data rows; first page = start bound + 3 with a CP, second
page = the end bound alone; control: no ceiling ⇒ one page of 5).
Refs #732#736
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 U3. EnsureFolderIsEventNotifier granted the EventNotifiers
.HistoryRead bit (and registered the event-history source) only when a
real HistorianDataSource was wired at promotion time, and EnsureVariable
composed the AccessLevels.HistoryWrite bit from whether a
HistorianDataUpdater existed at materialise time — so an assignment
after the first apply left existing folders without event history and
existing nodes refused by the SDK's HistoryUpdate admission until a full
rebuild, and a source reset to Null never took the bit back.
The two setters now re-evaluate: HistorianDataSource walks every promoted
folder (bit + source registration, both directions), HistorianDataUpdater
recomposes the AccessLevel of every historized variable (Writable read
back off the node's own CurrentWrite bit). The Host's boot ordering is no
longer load-bearing.
Tests: NodeManagerCapabilityRefreshTests (late source lights the bit on
an already-promoted folder and a reset takes it back, live-event
subscription untouched; late updater grants HistoryWrite to historized
nodes only and a reset takes it back, authored Writable preserved).
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 02 P5. OpcUaPublishActor ran the whole apply — DeploymentArtifact
.Open, ParseComposition, AddressSpacePlanner.Compute and the sink
materialisation — on the opcua-synchronized-dispatcher, so a large
artifact serialised every live value batch (and, because the node
manager lock is the SDK's, every client Publish) behind the parse.
StartRebuild now runs Open + ParseDataPlaneAuthority + ParseComposition
+ Compute in Task.Run and pipes a PlanReady (or PlanFailed) back to Self;
only ApplyPlan — the sink passes — runs on the actor thread. Rebuilds are
applied strictly in arrival order (a plan is a diff against _lastApplied,
which only the apply advances): one in flight, later ones queue in
_pendingRebuilds while value/status batches keep flowing. The apply is
closed (CompleteAddressSpaceApply) and the RebuildCompleted reply sent on
every path, PlanFailed included. The bytes-less ConfigDb fallback
(LoadArtifact / LoadLatestArtifact) is deleted: it had no production
producer and would have blocked the pinned thread on central SQL; the
dbFactory Props/ctor parameter is kept for wiring compatibility (F4).
Tests: OpcUaPublishActorOffThreadPlanTests — a value batch sent right
after a 50k-tag rebuild lands before that rebuild's first materialise
call (positive control: all 50k tags still materialise); back-to-back
rebuilds apply in arrival order (the second diffs against the first);
unreadable bytes answer degraded with nothing torn down. The rebuild /
apply-failure suites now hand the actor the artifact bytes every
production producer carries (SealArtifact records them; Rebuild(dep)).
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 U2. The composer never emits EquipmentTags in v3 (device values
live in the Raw subtree and reach equipment as UnsReferenceVariables), so
the equipment-tag plan diff sets (Added/Removed/ChangedEquipmentTags,
EquipmentTagDelta), the planner's diff over them, the classifier's
TagDeltaIsSurgicalEligible and its Rebuild clause, the applier's
MaterialiseEquipmentTags pass, surgical ChangedEquipmentTags loop,
removed-tag teardown loop and add-announcement term, and the publish
actor's equipment-tag pass were unreachable, maintained dead weight.
IsEmpty keeps its semantics (an otherwise-empty plan is still Empty).
Kept, deliberately: AddressSpaceComposition.EquipmentTags and the
EquipmentTagPlan record — Runtime's DeploymentArtifact (outside this
lane) still assigns the empty set and the artifact parity tests assert
it; follow-up F2 removes both together.
Tests: the equipment-tag vehicle tests for PureRemove / AddRemoveMix /
the rebuild ratchet are re-expressed over raw tags (same applier paths);
the equipment-tag surgical and classifier tests are deleted (their raw /
UNS-reference equivalents already exist); SubscriptionSurvivalTests now
materialises its tags through MaterialiseRawSubtree.
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 L3/H5/H4/P6/P4.
- L3/H5 OnEquipmentTagWrite's dispatch is factored into DispatchDeviceWrite:
a gateway that throws synchronously is refused inline with
BadDeviceFailure (it used to escape the handler under the SDK Lock), and
a faulted/cancelled dispatch task has its exception observed and logged
and carries the real reason into the revert/audit event instead of
surfacing as UnobservedTaskException at finalization.
- H4 every timestamp the manager stamps (condition quality, timed-shelve
expiry, method-transition events, carry-over, revert, revalidation)
reads the injected Clock; RemainingShelveMs takes the clock reading.
- P6 OpcUa:Quotas:* (OpcUaQuotaOptions on OpcUaApplicationHostOptions):
Min/MaxRequestThreadCount, MaxQueuedRequestCount with the former
hard-coded 5/100/200 as defaults, and the TransportQuotas members as
nullable overrides over the SDK defaults.
- P4 the SDK line exposes IHistoryReadAsyncNodeManager but CustomNodeManager2
offers no async virtual to override (adopting it means re-implementing
the base dispatcher), so the lever is the admission cap:
MaxConcurrentHistoryReadBatches defaults to clamp(2*ProcessorCount, 4, 16).
The Host still overrides it from ServerHistorianOptions (default 16) —
follow-up F3.
Tests: NodeManagerWriteDispatchTests (sync throw refused; faulted task
reverts; success leaves the value; clock-stamped revert),
OpcUaApplicationHostQuotaTests.
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 P1/P2/P3/P5 — work done under the manager-wide SDK Lock on the
pinned publish thread, where every Read/Browse/Publish waits.
- P1 RebuildAddressSpace detaches the shared root's top-level children
once instead of every leaf from its parent (NodeState.RemoveChild is a
linear scan + RemoveAt, ~k²/2 compares per k-child folder); root
notifiers are cleared as a list instead of one O(F) RemoveRootNotifier
each; ForgetPredefinedSubtree / TombstoneMonitoredSubtree are iterative
with one child buffer.
- P2 RemoveEquipmentSubtree walks a parent→children index maintained by
EnsureFolder/EnsureVariable/MaterialiseAlarmCondition (keyed by the
parent id the caller named) instead of prefix-scanning six maps per
removed equipment; a surviving condition's wiring into a removed folder
is found through the folder's own notifier list; descendants are not
detached from a folder that is itself being discarded.
- P3 LowerAllEventsMonitoring(condition) replaces the full O(C) reconcile
on RemoveAlarmConditionNode / RemoveEquipmentSubtree / the kind-swap.
- P5 AlarmNotifierWiring.Folders is a reference-identity HashSet and an
already-wired pair skips the SDK's linear AddNotifier dedup.
Benchmark (NodeManagerLockTimeBenchmarkTests, M-series Mac under load,
three runs each): rebuild of a 10k-tag folder 75–150 ms → 5–6 ms;
removing 200 equipment (250 signals each) from a 50k-node space
471–681 ms → 58–64 ms; all-events bookkeeping visits for 10 condition
removals over 50 conditions 900 → 10. The two timing legs assert < 1 s;
the P3 leg asserts the visit count (machine-independent).
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 L2. The SDK keys its fan-out lists by NodeId and its component
cache hands back the CACHED NodeState for a NodeId it already holds, so a
rebuild or a surgical remove+re-add left a NEW item on the same NodeId —
from any session — bound to the DEAD node: created Good, fed its stale
initial value, never again, until every session had deleted its items.
Every removal path (RebuildAddressSpace, RemoveVariableNode,
RemoveAlarmConditionNode incl. the condition's instance-scoped children,
RemoveEquipmentSubtree) now queues BadNodeIdUnknown to the node's data
items, drops the MonitoredNodes entry, releases each item's component
cache reference and forgets the _liveItems/_eventItems entries. Items
the ACL pass stood down (on no fan-out list) are swept by NodeId. A later
client delete of an orphaned item is completed by the DeleteMonitoredItem
override / the SubscribeToEvents unsubscribe arm instead of answering
BadMonitoredItemIdInvalid or NRE-ing in MonitoredNode2.Remove. The
revalidation restore re-resolves the node by NodeId and no longer
re-attaches to Handle.Node blindly. Timestamps now come from the injected
Clock (UtcNow).
Tests: StaleMonitoredNodeWireTests (real SDK, three legs: rebuild,
surgical remove+re-add, second session; each keeps the old item alive,
proves the new item receives a value written after its creation, the old
one gets BadNodeIdUnknown, and its delete succeeds — all three fail with
the tombstone neutered), NodeManagerStaleMonitoredNodeTests (stood-down
item swept on surgical remove and rebuild; sibling removal leaves it
restorable).
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Review 01 L1/L4/H2. WriteValue/WriteValues are non-creating (an unknown
id is skipped, counted and Debug-logged, as WriteStatuses always was), so
a driver publish racing a surgical remove can no longer resurrect the id
as a flat BaseDataType phantom under the shared root — nor hand a later
re-add of the same tag the phantom's parent/DataType/writability through
EnsureVariable's early return. WriteAlarmCondition for an unmaterialised
id is a logged no-op instead of minting the legacy bool[2] placeholder
(AddPredefinedNode is AddOrUpdate, so it replaced the SDK lookup entry of
any folder sharing the id). The applier no longer writes a condition
state against every removed equipment id (a folder, never a condition).
EnsureFolder/EnsureVariable/MaterialiseAlarmCondition refuse an id already
held by another node kind in the same realm. CreateVariable is deleted.
Tests: NodeManagerPhantomNodeTests (publish racing a remove leaves no
node; the re-add gets the authored shape and is live; unknown alarm id
is a no-op; the guard in all three directions, realm-qualified); the
sink / batch-write / write-statuses tests now declare their variables.
Refs #732
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- RunWriteAsync wraps the invoker call in WaitAsync(writeTimeout) (Props,
default 10 s = 2x the 5 s write cap): a token-ignoring hung write now
answers BadTimeout, releases its slot and tag, and its orphan outcome
is observed and discarded - later writes to that tag reach the device.
- WriteCompleted carries the launching incarnation (from the process-wide
generation source); a late completion from a previous incarnation after
a supervision restart is ignored instead of freeing the new
incarnation's slot/tag.
- Test: a hung token-ignoring tag-a write is abandoned and a later tag-a
write reaches the device while the abandoned one is still inside it.
Refs #731
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- GatewayHistorianDataSource.ReadRawWindowAsync keeps the cap + 1 probe budget
(budgetCap) separate from the client's cap: a strict-ceiling or crowding
refusal now reports Limit = the server cap that applied and advises setting
NumValuesPerNode at or below it (it said "lower NumValuesPerNode" with
Limit = cap + 1 to a client that sent 0).
- Fuzz: the oracle-source over-cap assertion was vacuous (cap 0 never counts);
it now checks no reverse window reached the forward-only shape. Class docs
name the post-floor cap set (3 ... 1000) and distinguish NumValuesPerNode
1 / 2 from the smallest server cap.
- HistoryPaging.IsFullPage doc says it judges the REQUEST cap (page + ties +
lookahead), which is finite under any limit; AdvertiseMaxReturnDataValues
swallows any exception (returns false for the caller to log), as its doc
promised.
Refs #736
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- 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
- NodeManagerHistoryReadRawCapFuzzTests: 10k seeds (env OTOPCUA_PAGING_FUZZ_ITERATIONS)
through a real SDK node manager against wire-faithful fakes of SqlServer / QuestDB /
Gateway that enforce the backend half of the cap; random series with ties, random
windows (empty, on/past a tie, between samples, forward/reverse/end-only, bounds),
N in {0,1,2,small,huge}, cap in {off,3..1000}, tie budget {3,8,65536}. Pages must
concatenate to the cap-off one-shot answer (checked against the series), terminate
within values + 2 (+ one empty step per oversized boundary cluster), never exceed
the cap, never ask the backend for 0 / over-cap; refusals only past the budget.
- HistoryPaging.AdvertiseMaxReturnDataValues writes HistoryServerCapabilities/
MaxReturnDataValues (i=11273), read back through the SDK master node manager.
- MinMaxRawValuesPerRead raised to 3: at 2 a resumed page has no room (value + its
boundary tie + lookahead) and every value cost an empty page + CP (seed 15).
- RawPageLimit rows pin the default-cap arithmetic (9 999 first page, 9 998 resumed).
Fuzz findings recorded as follow-ups: a bounded read whose data fits one page
returns cap + 1 (end bound fitted against N, not the cap; node manager, F2);
the Gateway walk-back's cost on a sparse series under a tiny tie budget is
pre-existing (seed 320: 82 reads uncapped, 93 capped).
Refs #736
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
Review R08:1.1: an uncapped HistoryRead-Raw (NumValuesPerNode = 0) read a
tag's whole window into memory on every backend (SQL TOP(int.MaxValue),
QuestDB LIMIT, Gateway max_values = int.MaxValue + a second snapshot copy).
New ServerHistorian:MaxRawValuesPerRead (default 10 000; <= 0 unbounded with
a Validate() warning; 1 raised to 2). Each backend data source takes it,
reports it as IHistorianDataSource.MaxRawValuesPerRead (the Gateway: min
with a strict gateway's learned ceiling), so the node manager's existing
RawPageLimit paging serves N = 0 and N > cap as pages of at most the cap
with a continuation point. Independently, a backend raw read asking for 0
or more than the cap reads cap + 1 rows and is REFUSED
(HistoryReadLimitExceededException => BadTooManyOperations) when the window
holds more - never answered truncated, since the server's paging reads a
short answer as the last page. Bound through the Host registry, the
SqlServer/QuestDb providers and GatewayHistorian.CreateDataSource.
Tests: options (default/binding/warnings), provider binding, Gateway unit +
through a real SDK node manager (uncapped -> 999/998/998/605 + CPs), and a
conformance case for the SQL backends.
Refs #736
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
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.
F1 (pre-existing): SliceTieCluster continued a forward read while next <= endUtc, but the
forward window is end-exclusive; an oversized cluster one step below EndTime resumed AT
EndTime, the resume became a start == end point read and returned the EndTime samples as
data (microsecond: EndTime 8.1 us truncated to 8.0). Continue only while next is strictly
before EndTime truncated to the backend resolution.
Tests: A_tie_cluster_just_below_the_end_time_never_resumes_onto_the_end_time (native +
microsecond; both fail on the old rule) and
A_cursor_inside_a_tie_cluster_over_fetches_without_a_normal_read_first (pins the
WithinTieCluster shortcut by per-page read count; fails with the shortcut disabled).
Docs: the oversized-cluster exception to 'every page full / no lookahead => last' (F2),
and the N + skip + 1 strict-ceiling edge note referencing #694 (F4).
Review follow-up: on the Gateway every value is a Double (AVEVA stores a Boolean
as a 0/1 Int2), so the raw-evaluated AtTime interpolated a Boolean node to 0.5.
- IHistorianDataSource gains a default-interface overload
ReadAtTimeAsync(fullReference, timestamps, TypeCode? valueType, ct) that
forwards to the existing one (SqlServer/QuestDB/Null/fakes unchanged).
- OtOpcUaNodeManager.HistoryReadAtTime passes the node's scalar DataType
(AtTimeValueType: built-in type -> TypeCode; arrays/other types => null);
Raw and UNS NodeIds alike.
- GatewayAtTimeReader converts each raw row to the hinted kind BEFORE the shared
AtTimeEvaluator runs (Boolean = value != 0 => stepped; integers => Int64 =>
interpolated, rounded half away from zero, returned as the node's integer
type; floats Double), so the evaluator's own type branch decides.
- AtTimeEvaluator boxed every interpolated Int64 as a Double (`cond ? (long)x :
v` widens to double); its "keeping its type" test passed because Shouldly
ShouldBe compares numbers across types. Fixed (affects SqlServer/QuestDB too)
and pinned with ShouldBeOfType.
A resumed raw page asked the backend for only N rows from the boundary timestamp
(inclusive), then trimmed the boundary ties already emitted: it netted N - skip values,
and at N = 1 nothing — the empty "full" page was taken for a stalled tie cluster and a
MaxTieClusterOverfetch + 1 (65,537-row) over-fetch stepped one tick, returning an EMPTY
page with a continuation point between every value (8 values = 17 pages / 25 reads),
forward and reverse, with or without ReturnBounds, on every backend.
Each page's read now asks for N + boundarySkip + 1 rows: the ties it trims, the page and
one lookahead row. The lookahead row is the 'more data' signal, so an exact multiple ends
on its last full page (no trailing empty page). The over-fetch fires only when every row
past the trimmed ties is still on the boundary (a genuine cluster larger than the page);
a cursor left inside a cluster is flagged WithinTieCluster and over-fetches directly.
A page that never leaves the boundary adds the prior skip to its cursor.
Low items: BoundedReadHasAnythingAsync carries its walk hint and, when there is no data,
the end bound it found (HistoryEndBound.Resolved + DataExhausted), so the next page reads
nothing; HistoryBounds.IsPlaceholder is an explicit marker (ConditionalWeakTable over the
NotFound instances) instead of status+null shape, so a stored Bad_BoundNotFound row is data.
Tests: NodeManagerHistoryReadPageFillTests (N=1 every shape/direction/bounds, tie clusters
straddling boundaries at N=1/2/3, exact-multiple, carried end bound + walk hint, stored
placeholder-shaped row). Existing paging tests updated where they encoded the short pages.
1. The at-or-after bound read on a forward-only backend (Gateway) ends at
now + ReverseRawReader.LookAhead instead of DateTime.MaxValue (the gateway
only checks start <= end, so a year-9999 end reached AVEVA); a bound beyond
the horizon is not found without a read. SqlServer/QuestDB keep MaxValue:
they bind it safely and may hold samples further ahead. The Gateway fake now
refuses far-future ends, so the missing-end-bound test is no longer vacuous.
3. No data and no bound found (whole read empty) => GoodNoData, no values —
the pre-bounds answer (6.5.3.2: success only if one or both bounds exist).
A one-value page whose start bound is missing first checks there is data or
a found end bound.
4. ServerHistorian:HonorReturnBounds (default true); false ignores ReturnBounds
as before #691, including the modified-read Bad_InvalidArgument.
The node manager composes the start/end bounds from each backend's existing raw
reads (one authority, HistoryBounds): at-or-before = a capped reverse read
(native, or ReverseRawReader's walk-back on a forward-only backend — never
AVEVA's synthetic boundary row), at-or-after = a capped forward read. Bounds
count toward NumValuesPerNode, the start bound leads the first page, the end
bound ends the last (carried in the continuation point). Missing bound =
Bad_BoundNotFound (null, at the bound time; one-sided reads ±1 s from the
previous value, Table 1 footnotes a/b). A modified read with ReturnBounds is
Bad_InvalidArgument (Part 11 6.5.3.3).
The .NET SDK's ReadRawModifiedDetails defaults ReturnBounds to TRUE; the
existing tests built details without setting it and now set it false.
Oracle: every row of Part 11 Table 1 over three backend shapes, plus paging
concatenation, ties, Bad bounds, microsecond truncation; conformance pins the
lookup primitives on SqlServer + QuestDB.
A tie cluster's truncated read left the width at one tick; once the gap
above it was under two milliseconds nothing floored it, so segHi
stepped down one tick per read: 30 rows at one ms 0.3 s below hi with a
carried 1 s width took 10,006 identical reads (S8). (a) The top-anchored
width is floored at the granularity, Min kept; (b) a segment no wider
than the granularity is the unit that escalates to
MaxTieClusterOverfetch and then refuses - per millisecond, exact for the
ms-resolution Gateway (documented). Both are needed: the floor alone
loops on crowded reads with a small tie budget. S8 is a repo test
(4 shapes, reads <= 30, 0 repeated requests); random-data tests now
measure the refusal unit as rows in any 1 ms window. Reviewer harness,
5,000 seeds x default/MSONLY/CROWD: worst page 70 reads (default/MSONLY),
63 (CROWD) at M=65536, p99.9 27-37; no page over 500 reads at any tie
budget.
Bisecting the gap above a truncated read halved below the 1 ms request
granularity (requests are ms-rounded, so it re-sent identical requests)
and bisected the WHOLE gap even when the burst ended right above the
row it saw: a 1,026-row burst ending 100 days ago took 46 reads. After
an empty top-anchored segment the walk now gallops up from the known
row ((known + d, top], d x4, following each truncated read), then
bisects the bracket, with halving floored at the granularity (the Min
kept; a crowded gallop falls back to top-anchored halving). Burst: 18
reads, 0 repeated requests; dense tag stopped 2 days ago: 26 (gallop
alone crawled: 94). Walk fuzzed at 4,000 seeds locally (400 in-tree).
Docs: measured counts; CLAUDE.md gateway prerequisites list
RuntimeDb:EventReadMaxRows.
A reverse or end-only capped events read on a backend without
SupportsReverseEvents (Gateway, Null) was refused
BadHistoryOperationUnsupported (explicit reverse) or answered with the
OLDEST N ascending (end-only, #675). It is now served newest-first by
the same ReverseWalk as raw reads: page-sized ms-aligned segments,
never answered from a read the source flagged truncated, ties sorted by
EventId (the gateway orders by event time only - the fake shuffles
them per call), one extra event walked to signal 'more', uncapped = one
forward read reversed, and the width + proven-empty stretch carried in
the events cursor. The oversized-cluster over-fetch keeps exactly the
events at T in the same order. A tie cluster over the budget is
BadTooManyOperations. Docs note the gateway's EventReadMaxRows must be
unlimited (it truncates silently).
The last pages of a deep reverse page-through on a forward-only backend
each walked down to 1970 one x4 growth step at a time (~14-16 reads,
~2.5 s live). After two empty segments the walk now asks once per page
for the whole remainder at the page budget (a truncated answer is
discarded and the walk carries on), and the stretch the page's last
complete read proved empty rides the continuation point
(HistoryContinuationState.EmptyFromTicks/EmptyToTicks, session-held, so
no versioning) so the next page steps over it. Fuzz now pages with the
walk's own hints and with true random empty stretches.
ReverseRawReader aimed every segment at half of MaxTieClusterOverfetch
(~32k rows by default) and carried that width page to page, so a paged
'latest N' read on a dense Gateway tag fetched ~32,770 rows per page
(2-5 s live) to return N. The walk now lives in a generic ReverseWalk
core: segments are aimed at ~N+8 rows (page budget 2N+16), a discovery
segment (first without a hint / after an empty one) may read 1,024, and
the tie budget is only the ceiling a single-timestamp cluster escalates
to. A truncated read never re-enters the stretch below its newest row
until the gap above it is bisected. Tests: per-page row counts on a
dense tag (node manager + walk), randomized exactness fuzz (walk and
node-manager paging), dense-tag-below-a-long-gap read bound.
1. Uncapped reverse raw read on a forward-only backend = ONE forward read of the
window, filtered and reversed in memory (was a segment-by-segment walk).
2. Segment width is aimed at ~half the row budget from the density just observed
(overflow: from the truncated read's own sample span) and carried page to page
in HistoryContinuationState.SegmentWidthTicks.
3. The walk starts no later than now + 1 day and never reads before the epoch.
4. Request bounds are rounded outward to the millisecond, so a row AVEVA
fabricates at a rounded-up query start cannot land inside the segment.
5. Budget M = max(1, MaxTieClusterOverfetch); reads ask M + 2 rows, completeness is
'short OR last row past the segment', and a read crowded by rows before the
segment is re-read once (<= 2M + 4). A cluster of exactly M, neighbouring
clusters each within M, and M <= 1 are all served; only one timestamp over M
is refused. ServerHistorianOptions text updated.
6. The raw and events tie-path oversized-cluster refusal is BadTooManyOperations
(was BadHistoryOperationUnsupported), consistent with the walk.
7. GatewayHistorianDataSource.ReadRawAsync: a caller cancellation is not a backend
failure; NumValuesPerNode = 0 is sent as int.MaxValue (the client package and
the gateway reject max_values <= 0, so every uncapped Gateway raw read failed);
a MaxValuesCeiling refusal is a HistoryReadLimitExceededException.
8. Tests: upper-edge filter, epoch floor, look-ahead, ms alignment, exact/adjacent
clusters, minimal budget, carried density, and the walk over the real Gateway
source + FakeHistorianGatewayClient (OpcUaServer internals visible to it).
#669 turned an end-only capped HistoryRead-Raw into a reverse read (start > end)
for every backend; the gateway rejects start > end (InvalidArgument), so on the
default Gateway backend every end-only capped and every explicit reverse raw read
failed the node and was counted as a backend health failure.
- IHistorianDataSource.SupportsReverseRaw (default false; SqlServer/QuestDB/Null
true, Gateway false; guard test pins that every production backend declares it).
- OtOpcUaNodeManager sends a reverse window only to a backend that declares it;
otherwise ReverseRawReader walks (lo, hi] back in bounded forward segment reads
(1 min, x4 while sparse; each <= MaxTieClusterOverfetch + 1 rows; a full read is
re-read narrower, never answered truncated; filtered on sample timestamps, which
also drops AVEVA's fabricated query-start rows; stops at the Unix epoch). A
one-timestamp tie cluster over the bound => BadTooManyOperations.
- ServeRawPagedAsync maps HistoryReadLimitExceededException to BadTooManyOperations.
- GatewayHistorianDataSource.ReadRawAsync refuses start > end unsent, without
recording a health failure.
- #682: ServedAggregates (ten raw-evaluated per-sample + TimeAverage/Total) replaces the placeholder
AggregateModeMapper.Served; NativeAggregates is derived from the mapper's switch. The Gateway
expectations in AggregateModeMapperTests, HistorianBackendRegistryTests and
AdvertisedAggregateFunctionsWireTests move to the 12-member set (the wire tests' 'not served by
Gateway' example is now TimeAverage2).
- #684: RawBucketAccumulator applies the SQL backends' Good-only value columns (Avg/Min/Max/Sum and
the ActualTime extreme over Good numeric samples), UncertainMin/UncertainMax over Uncertain numeric
samples, and GoodNonNumeric. The parity oracle carries the #684 InMemoryRows and the DenseUncertain /
UncertainBeyond / UncertainText datasets.
Average, Count, Minimum, Maximum, Range, Start, End, Delta and Minimum/MaximumActualTime are evaluated
on the Gateway backend from forward ReadRaw reads with BucketPlan + AggregateEvaluator, so Gateway
matches SqlServer/QuestDB exactly (values, status bits, interval-start stamps, #677 reverse).
- Window read [start - 1 ms, end] so AVEVA's initial-value row never lands in a bucket; a pre-window
row proves earlier data only with a non-Bad OPC quality (histsdk puts a value on every NULL row).
- Earlier data otherwise from a 2-row [1970, start) probe; later data from a 2-row [end, now+1d]
look-ahead; both ignore rows stamped at their query start/end.
- No gateway stream is ever abandoned (a client-side cancel makes the gateway evict its shared
historian session); past ServerHistorian:MaxTimeWeightedRawRows the bounded stream is drained, then
BadTooManyOperations. The gateway's max_values-ceiling InvalidArgument maps to the same limit; a
caller cancellation is not a backend fault.
- TimeAverage/Total stay AVEVA-native (no prior-sample read for exact Part 13 bounds), now stamped with
the interval start (PENDING the live leg: histsdk's tail+43 start_time field is unverified) and
carrying the Calculated bits.
- Served set: GatewayHistorianDataSource.ServedAggregates (12). Live AVEVA leg open (VPN).
Joseph Doherty