Closes arch-review remediation residual #1 (DCL unsubscribe-during-reconnect
count staleness).
DataConnectionActor tracked TotalSubscribedTags/ResolvedTags as two int fields
incremented and decremented at five independent sites. ReSubscribeAll clears the
very maps those decrements key off (_subscriptionIds, _unresolvedTags) while
deliberately preserving _subscriptionsByInstance, so an unsubscribe landing
inside a reconnect window matched NEITHER decrement branch: the total leaked +1
per subscribe/reconnect/unsubscribe churn cycle, permanently and cumulatively.
The 37f13e2e discard gate stopped the orphan-handle half of that race; it could
not stop the counters drifting, because they were state of their own.
Both counts are now DERIVED at report time from the authoritative per-tag
collections, which makes the drift unrepresentable rather than merely guarded:
total = _instancesByTag.Count (the per-tag counted set the residual
called for — distinct tags with at least
one subscribing instance)
resolved = _subscriptionIds.Count (tags for which the adapter holds a handle)
Two semantic corrections fall out of the derivation:
- A tag whose subscribe failed at CONNECTION level now counts toward the total.
It was excluded before, yet the reconnect re-subscribe re-issued it from
_subscriptionsByInstance and booked it as resolved — resolved above total, and
a total driven negative by the eventual unsubscribe.
- _tagSubscriberCount is deleted. It duplicated _instancesByTag exactly, so
HandleUnsubscribe's last-subscriber test is now "did UnindexTag drop the key?"
— still O(1), with no parallel count that can disagree about when a handle is
released. The subscribe-success promotion split (fresh vs. unresolved→resolved)
also goes: it existed only to pick which scalar to bump; set sizes get
DataConnectionLayer-020's double-count cases right for free.
Behavior is otherwise unchanged — same logging, same handle release, same
unresolved-tag probing, same in-flight-unsubscribe discard semantics (the long
comment block there is updated for the mechanics that changed).
Tests: five TagResolutionCounts_* cases in DataConnectionActorBatchTests
covering the churn repro (3 cycles), a shared tag losing one instance mid
reconnect, connection-level failure then recovery, plain subscribe/unsubscribe
cycles, and a completed reconnect re-subscribe. Verified failing against the
pre-fix actor (churn: total 1 not 0; connection-level: total 0 not 1) and
passing after. Full DCL suite 319/319; solution builds with 0 warnings.
Docs: Component-DataConnectionLayer.md health-reporting section describes the
derived counts; residuals register item 1 marked RESOLVED.
Expanding a Galaxy object in the tag picker hung on "loading…": the browse
reply inlined every child's full attribute set (~152 KB), exceeding Akka's
128 KB remote frame, and remoting silently discarded the oversized reply.
Browse path (DataConnectionLayer):
- RealMxGatewayClient: navigation now uses BrowseChildren(include_attributes=
false) — child objects only — and an object's own attributes load lazily via
DiscoverHierarchy(root, max_depth=0) when it's expanded. Payload drops from
~152 KB/level to a few KB. Seam contract unchanged.
- DataConnectionActor.CapBrowseChildren: protocol-agnostic byte-budget cap
(~100 KB) on every BrowseNodeResult before it crosses the site→central
frame, OR-ing the adapter's own Truncated flag. Byte budget, not a count —
the only bound that holds regardless of NodeId/attribute-name length.
- RealOpcUaClient: requestedMaxReferencesPerNode 1000 → 500 to narrow the
window before the byte budget applies.
- Graceful gRPC Unimplemented handling → NotSupportedException →
BrowseFailureKind.NotBrowsable with an actionable message (older gateway
builds lacking BrowseChildren).
Picker UI (CentralUI):
- NodeBrowserDialog: modal-lg → modal-xl; new scoped .razor.css caps the tree
at 55vh with its own scrollbar so manual entry + Select/Cancel stay visible.
- Protocol-agnostic failure messages (was hardcoded "OPC UA …"); renamed the
leftover opcua-browser-tree class to node-browser-tree.
Tests: new frame-budget cap test + NotSupported=>NotBrowsable mapping test;
DCL suite 88/88. Doc: Component-DataConnectionLayer.md records the lazy
attribute-light browse and the frame-size guard.
Adds a Test Bindings button to the Connection Bindings table on the Configure
Instance page that opens a modal showing the live current value of every bound
attribute. Reuses the routing path that the OPC UA tag browser landed on:
Central: TestBindingsDialog → IBindingTester → CommunicationService
→ ReadTagValuesCommand → SiteEnvelope (Ask)
Site: SiteCommunicationActor → DeploymentManagerActor singleton
→ DataConnectionManagerActor → child DataConnectionActor
→ _adapter.ReadBatchAsync
Split mirrors the browse handler:
• Manager owns ConnectionNotFound (only it sees the per-site connection set).
• Child owns ConnectionNotConnected (pre-call status check, never stash —
read is interactive design-time), Timeout (OperationCanceledException),
ServerError (any other exception). Per-tag failures from ReadBatchAsync
become failure TagReadOutcomes without aborting the batch.
CentralUI:
• IBindingTester / BindingTester — Design-role guard via HasClaim against
JwtTokenService.RoleClaimType (not IsInRole — see c1e16cf), typed
transport-failure translation.
• TestBindingsDialog — ShowAsync(siteId, rows, instanceLabel) method-arg
pattern (no Razor parameter race; see 2c138b6), groups rows by connection
and issues one ReadAsync per connection in parallel, per-row error subline
+ per-connection banner, Refresh button re-issues the reads.
• InstanceConfigure.razor — Test Bindings button next to Save Bindings,
disabled when no testable rows. OPC UA only today (other protocols have
no ReadTagValuesCommand wiring yet).
Tests:
• Commons: ReadTagValuesCommand discovered by ManagementCommandRegistry.
• DataConnectionLayer: unknown connection → ConnectionNotFound,
not-connected adapter → ConnectionNotConnected (ReadBatchAsync NOT called),
success-path mapping (Good/Bad + per-tag error), cancellation → Timeout.
• CentralUI: register IBindingTester (and the previously-missing
IOpcUaBrowseService) on the existing InstanceConfigureAuditDrillinTests
Bunit container so the page renders cleanly with the new dialog.
- BrowseOpcUaNodeCommand: int DataConnectionId -> string ConnectionName
(site DataConnectionManagerActor indexes children by name; CentralUI
already has the connection name in scope via the dropdown — no extra
plumbing across the trust boundary).
- IOpcUaBrowseService / OpcUaBrowseService: parameter renamed accordingly.
- OpcUaBrowserDialog: collapse the duplicate ConnectionName parameters
(display label and routing key are the same string).
- Task 10: DataConnectionManagerActor forwards BrowseOpcUaNodeCommand to
its child by name (owns ConnectionNotFound); DataConnectionActor adds
the receive across all three lifecycle states (Connecting / Connected
/ Reconnecting) and maps adapter outcomes to BrowseFailureKind
(NotBrowsable / ConnectionNotConnected / Timeout / ServerError).
- Task 17: SetFailure in OpcUaBrowserDialog implements the full
BrowseFailureKind switch with friendly UI messages.
- Tests: DataConnectionManagerBrowseHandlerTests covers ConnectionNotFound,
NotBrowsable, success, and ConnectionNotConnectedException paths.
Joseph Doherty