Complete implementation of **OPC UA Part 9 ΓÇö Alarms & Conditions** for
both server and client, **OPC UA Part 16 ΓÇö State Machines** (generic
extensible client + server API), and the supporting infrastructure
(source-generated event records, source-generated ObjectType proxies,
`IAsyncEnumerable` streaming subscriptions, address-space model change
tracking, per-node `INodeCache` invalidation, unified DI integration).
### Server-side (Part 9 complete)
- **`AlarmConditionState`** ΓÇö every Part 9 method wired automatically
in `OnAfterCreate`: `Silence`, `Suppress`/`Suppress2`,
`Unsuppress`/`Unsuppress2`, `RemoveFromService`/`RemoveFromService2`,
`PlaceInService`/`PlaceInService2`, `Reset`/`Reset2`,
`GetGroupMemberships`. Each method generates the spec-mandated audit
event and supports an optional veto-delegate hook.
- **Latched alarms** ΓÇö `ActiveState` reflects real process state;
`LatchedState` persists until explicit `Reset` (with full precondition
validation).
- **Re-alarming** ΓÇö
`ProcessReAlarm`/`ResetReAlarmRepeatCount`/`IsReAlarmEnabled` helpers
(opt-in, no hidden timer).
- **Audible alarms** ΓÇö `UpdateAudibleState` for
`AudibleEnabled`/`AudibleSound`/`SilenceState` lifecycle.
- **Suppression + groups** ΓÇö `AlarmGroup`, `AlarmSuppressionEngine`
(with first-in-group), `AlarmRateTracker` (for `AlarmMetricsType`).
- **Spec-compliance fixes** ΓÇö `SuppressedOrShelved` now includes
`OutOfServiceState`; `GetRetainState` includes `LatchedState`;
`EffectiveDisplayName` composition includes `OutOfServiceState` +
`LatchedState`.
### Client-side Part 9 API
- **`AlarmClient`** ΓÇö typed Part 9 operations. Each method delegates
to the matching source-generated `*TypeClient` proxy
(`ConditionTypeClient`, `AcknowledgeableConditionTypeClient`,
`AlarmConditionTypeClient`, `DialogConditionTypeClient`,
`ShelvedStateMachineTypeClient`) ΓÇö one source of truth for every
method NodeId.
- **Interface hierarchy** — `IConditionOperations` →
`IAcknowledgeableConditionOperations` → `IAlarmOperations` +
`IDialogConditionOperations`.
- **Source-generated event records** ΓÇö new `EventRecordGenerator`
(alongside `ObjectTypeProxyGenerator`) emits `{Type}TypeRecord` per OPC
UA event type: `ConditionTypeRecord` →
`AcknowledgeableConditionTypeRecord` → `AlarmConditionTypeRecord` →
`LimitAlarmTypeRecord`/`ExclusiveLimitAlarmTypeRecord`/… all the way
to vendor subtypes. **Vendor alarm types get records automatically.**
- **`AlarmEventDecoder`** ΓÇö decodes `EventNotification.Fields` into
the most-specific generated record.
- **`AlarmEventFilterBuilder`** ΓÇö fluent builder for Part 9
`EventFilter`s.
- **`ISession.GetAlarmClient(telemetry)`** convenience extension.
### Part 16 state machines (generic, extensible)
- **Client**: extension methods on the source-generated
`StateMachineTypeClient` / `FiniteStateMachineTypeClient` ΓÇö
`GetCurrentStateAsync`, `ObserveFiniteTransitionsAsync`
(`IAsyncEnumerable<FiniteStateSnapshot>`), `WaitForStateAsync`,
`GetAvailableStatesAsync` / `GetAvailableTransitionsAsync`. **Vendor
proxies inherit the API automatically** through the generated
inheritance chain.
- **Server**: `StateMachineBuilder` (fluent: `AddState` /
`AddTransition` / `OnCause` / validation) +
`FluentFiniteStateMachineState` ΓÇö declare a Part 16 state machine
without subclassing the abstract base.
- **Alarms alignment**: `AlarmClient.GetShelvingStateAsync` /
`ObserveShelvingTransitionsAsync` surface the API for every alarm's
`ShelvingState` child.
### IAsyncEnumerable streaming subscription
- **`IStreamingSubscription`** with
`SubscribeDataChangesAsync`/`SubscribeEventsAsync` returning
`IAsyncEnumerable<T>` (Channel-backed).
- **`ManagedSession.DefaultStreaming`** ΓÇö lazy shared subscription;
disposed with the session.
- **Helpers** ΓÇö `TakeUntilAsync`, `WithTimeoutAsync`, `TakeAsync`,
`BufferedAsync` for state-machine waits and bounded observation windows.
- **`AlarmStreamExtensions`** ΓÇö
`SubscribeAlarmsAsync`/`SubscribeConditionsAsync`/`SubscribeDialogsAsync`
returning the source-generated record types.
### Address-space model change tracking
- **Server**: `RaiseGeneralModelChangeEvent` on both `CustomNodeManager`
and `AsyncCustomNodeManager`; `ModelChangeAggregator` (in
`Opc.Ua.Server.NodeManager`, used by every node manager) batches changes
per service call; **auto-emit** from `CreateNode`/`DeleteNode` (opt-out
via `ModelChangeEmissionEnabled = false`).
- **Client**: `IModelChangeTracker` subscribes to
`BaseModelChangeEventType` via the streaming subscription, decodes
`ModelChangeStructureDataType` payloads, invalidates the `INodeCache`
per-node.
- **`INodeCache.InvalidateNode(NodeId)`** ΓÇö new interface member (true
per-node eviction in `NodeCache`).
- **`ManagedSession.EnableModelChangeTrackingAsync()`** +
`ManagedSessionOptions.ModelChangeTracking` +
`ManagedSessionBuilder.WithModelChangeTracking()` fluent method.
### Dependency Injection integration
- **`services.AddOpcUa().AddClient(...).AddAlarms()`** ΓÇö registers
`AlarmClientFactory` so DI-hosted apps can resolve a Part 9 client per
session without `new`-ing one manually.
- Cross-link added to the unified DI surface (`AddServer` / `AddClient`
/ `AddComplexTypes` / `AddGdsServer` / `AddLdsServer` /
`AddWotConServer`).
### Quickstart server modernization
- `Quickstarts.Servers/Alarms/AlarmNodeManager.cs` ported to
`AsyncCustomNodeManager` and demonstrates the new `AlarmGroup` +
`AlarmSuppressionEngine` end-to-end via a writable `MaintenanceMode`
boolean that suppresses every member alarm.
### Documentation
- New: `Docs/AlarmsAndConditions.md`, `Docs/StreamingSubscription.md`,
`Docs/ModelChangeTracking.md`, `Docs/StateMachines.md` ΓÇö full
developer guides.
- Updated: `Docs/DependencyInjection.md` (`AddAlarms()` row + section),
`Docs/README.md` index, `Docs/MigrationGuide.md` (Part 9 / Part 16 /
model change tracking sections covering behavior changes + breaking API
surface).
- Sample: `Applications/ConsoleReferenceClient/AlarmClientSample.cs`.
## Proposed changes
This PR updates the server monitored-item pipeline to be
`IAsyncNodeManager`-aware and introduces channel-based FIFO queueing in
the monitored-node path to improve behavior under load.
It also includes follow-up fixes from review/CI feedback:
- Adjusted
`AsyncCustomNodeManagerTests.WriteAsync_PublishesValueToMonitoredItemQueueAsync`
to account for channel-based delivery timing/coalescing while still
asserting the written value is observed.
- Merged latest `master` into this branch and resolved merge conflicts
(notably in `ConfigurationNodeManager`), keeping async address-space
lookup behavior intact.
- Applied small compile-safety corrections needed for successful
validation.
Drive the solution to zero warnings / zero errors with analyzers on,
promote the consistently-fixed rules to error, and lock in coverage
on the only line of new logic.
* Improve thread safety and logging in MonitoredItem
Replaced Queue with ConcurrentQueue in MonitoredItemDataCache
for thread-safe operations. Updated Publish method to use
List<DataValue> for better handling of dequeued values. Enhanced
logging to include SourceTime and added logs for dropped values.
In DurableSubscriptionTest, added try-finally block to ensure
proper session closure and disposal, preventing memory leaks.
Introduced DurableSubscriptionTestLooper for stress testing
under debug mode. Refactored test code for improved readability.
* Improve logging and session management
Updated logging in `Session.cs`, `ServerBase.cs`, and `UaSCBinaryClientChannel.cs` to pass exceptions directly to the logger, enhancing error handling. Added connection state checks in `Session.cs` to prevent operations when the session is closed or never connected. Updated `Subscription.cs` to reflect session disconnection in `PublishingStopped`. Enhanced test outputs and renamed `DurableSubscriptionTestLooper` to `DurableSubscriptionTestDebug` in `DurableSubscriptionTest.cs`, reducing loop count for faster debug testing.
* Fix monitored item id factory producing collisions by first trying to allocate a free monitored item id in the table, then committing.
* Better diffing
* Enhance logging and session management
Added detailed logging in `AlarmNodeManager.cs` for lifecycle events and simulation control. Introduced a `Reconnecting` property in the `ISession` interface and `Session.cs` to manage session reconnection state, replacing the `m_reconnecting` field. Enhanced logging in `Session.cs` for reconnection and publish operations. Updated `DataGenerator.cs` to use `FrozenDictionary` for performance improvements. Replaced `SyncRoot` with `m_syncRoot` in `NamespaceTable.cs` for synchronization. Improved exception message formatting in `ServiceResult.cs`. Added necessary namespaces for new data structures. Made corrections and added debugging in `DurableSubscriptionTest.cs` for better session handling.
* Dispose simulation
* Enable Durable Subscriptions (#9)
* [Server] Durable Subscriptions (#2683)
* Implement a system test for DurableSubscriptions (#2839)
* Client Side
Co-authored-by: ALTERNATE-DEV\Archie <archie@dreamsandadventures.ca>
* make a static Method CalculateRevisedQueueSize
* Adress review feedback
* fix FilterRetainTests
* Add MonitoredItem Id to Queues
Use NodeIdDictionary where possible
* first proto
* fix reference server
* implement store
* initialize early
* fix issues
* Move to Reference Server & start implementing queue restore
* Persist queues
* Register queues in factory after restore
* Add Docs
* minor fixes
* Test Subscription Restore & Transfer
* fix Durable Subscription Test Browse
* Fix conversion of extension objects
* use CustomConverter for NumericRange
* Adress review Feedback
* Documentation improvements
* Update Readme
* update sampling group manager to work without session
* remove launch settings
* Enable Durable Subscriptions (#9)
* [Server] Durable Subscriptions (#2683)
* Implement a system test for DurableSubscriptions (#2839)
* Client Side
Co-authored-by: ALTERNATE-DEV\Archie <archie@dreamsandadventures.ca>
* make a static Method CalculateRevisedQueueSize
* Adress review feedback
* fix FilterRetainTests
* Add MonitoredItem Id to Queues
Use NodeIdDictionary where possible
- Move the auditing flag to server internal
- Hook up new configuration setting to the Auditing node
- A Security Admin can change the Audit setting.
- Refactor audit events to be extensions in one class.
- enable auditing and diagnostics by default for higher test coverage.
- refactor dependency of some events to bindings, e.g. TcpServerChannel should not be used as reportevent parameter
- Implement client and server side of Transfersubscription service calls.
- New Transcription service has been tested with CTT 1.04.9.398
- Unit tests for native service calls and client SDK
- Client implements multiple ways to transfer sessions:
- Client saves subscriptions to xml stream, restarts, loads subscriptions from stream and transfers on server.
- Client creates a new sessions and transfers into new session, while the old session is still active.
- Client closes old session with `DeleteSubscriptionsOnClose = false`, creates new session and transfers subscriptions to new session.
- `SessionReconnectHandler` tries to transfer subscription before recreating the subscriptions.
- breaking change: INodeManager got a new TransferMonitoredItems method
Co-authored-by: Alexander Koepke <alexander.koepke@microsoft.com>
Co-authored-by: Peter Bryntesson <pbrynt@microsoft.com>
Marc Schier