diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs
index c8e4297f..8945623e 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs
@@ -1313,34 +1313,43 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
var candidates = fromNodes.Concat(fromTags).ToHashSet(StringComparer.Ordinal);
var plansByEquipment = _discoveredByDriver[driverId];
+ // Track whether ANY entry was dropped (no-longer-candidate or rebind) so we can re-trigger this
+ // driver's discovery exactly ONCE after the inner map is processed (see the post-loop block).
+ var droppedAny = false;
foreach (var equipmentId in plansByEquipment.Keys.ToList()) // snapshot — we mutate the inner dict
{
var plan = plansByEquipment[equipmentId];
if (!candidates.Contains(equipmentId))
{
plansByEquipment.Remove(equipmentId);
+ droppedAny = true;
_log.Debug("DriverHost {Node}: dropped cached discovered nodes for {Driver}/{Equipment} — equipment no longer resolves", _localNode, driverId, equipmentId);
continue;
}
// If the equipment was rebound (the cached plan's NodeIds are scoped to the OLD equipment), drop +
// let re-discovery rebuild against the new equipment. The plan's NodeIds are "{equipmentId}/...".
- // KNOWN LIMITATION (follow-up, alongside the multi-device-per-driver limitation): a
- // CONFIG-UNCHANGED rebind (the driver's DriverConfig is identical, only its authored tag's
- // EquipmentId moved) drops the cached plan here but does NOT itself re-trigger discovery —
- // ReconcileDrivers only restarts a child on a DriverConfig change, so a config-unchanged child is
- // never stopped/reconnected. The FixedTree subtree therefore stays ABSENT under the new equipment
- // until the driver's next reconnect/restart re-discovers it. We deliberately do NOT add re-trigger
- // logic here (it would couple the subscription pass to driver-lifecycle control); the drop is the
- // safe, correct fail-state (a stale EQ-1-scoped graft under EQ-2 would be worse).
var planEquipmentConsistent = plan.Variables.Count > 0
&& plan.Variables[0].NodeId.StartsWith(equipmentId + "/", StringComparison.Ordinal);
if (!planEquipmentConsistent)
{
plansByEquipment.Remove(equipmentId);
+ droppedAny = true;
_log.Debug("DriverHost {Node}: dropped cached discovered nodes for {Driver}/{Equipment} — equipment rebound", _localNode, driverId, equipmentId);
}
}
+ // Re-trigger discovery when ANY entry was dropped (no-longer-candidate or rebind). A CONFIG-UNCHANGED
+ // rebind (the driver's DriverConfig is identical, only its authored tag's EquipmentId moved) is NOT
+ // restarted by ReconcileDrivers — the child stays Connected — so without this nudge the FixedTree
+ // subtree would stay ABSENT under the new equipment until the driver's next natural reconnect. We now
+ // ask the child to re-run discovery so it re-grafts promptly: the next pass resolves against the new
+ // _lastComposition (the now-bound equipment). This is a DISCOVERY action, not lifecycle control — no
+ // stop/restart; it is idempotent, and the child no-ops it if not Connected (handled in
+ // DriverInstanceActor). Sent at most ONCE per driver per re-inject pass (here, after the inner map is
+ // processed — so even when the inner map empties below), guarded on the child still existing.
+ if (droppedAny && _children.TryGetValue(driverId, out var rediscoverEntry))
+ rediscoverEntry.Actor.Tell(new DriverInstanceActor.TriggerRediscovery());
+
if (plansByEquipment.Count == 0)
{
_discoveredByDriver.Remove(driverId);
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorDiscoveryTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorDiscoveryTests.cs
index e32d814c..f26dfa25 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorDiscoveryTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorDiscoveryTests.cs
@@ -460,6 +460,68 @@ public sealed class DriverHostActorDiscoveryTests : RuntimeActorTestBase
publish.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
}
+ /// Follow-up C, part 2: a CONFIG-UNCHANGED rebind must RE-TRIGGER discovery on the driver's child
+ /// so the dropped FixedTree re-grafts under the NEW equipment on the next pass (rather than staying absent
+ /// until the driver's next natural reconnect). Wires a REAL child (policy
+ /// , ever-growing set) so the connect-time pass populates the
+ /// per-equipment cache under EQ-1, then redeploys to rebind d1 → EQ-2 with the SAME (unchanged) DriverConfig
+ /// (so ReconcileDrivers does NOT restart the child — exactly the config-unchanged rebind). The
+ /// re-inject tail drops the stale EQ-1 entry and must send
+ /// to d1's child. The trigger reaching the child is observed at the host level (the only faithful seam — there
+ /// is no probe-as-driver-child seam): the child re-runs discovery (its DiscoverCount advances past the
+ /// single Once pass — impossible without the trigger, since the child stays Connected so nothing else re-kicks
+ /// discovery) AND a fresh re-grafts the FixedTree
+ /// under the new equipment EQ-2.
+ [Fact]
+ public void Config_unchanged_rebind_re_triggers_discovery_on_the_child()
+ {
+ var db = NewInMemoryDbFactory();
+ // A REAL ITagDiscovery child (Once policy) — so the connect-time pass populates the cache and a
+ // TriggerRediscovery re-runs discovery, making the trigger observable at the host level.
+ var factory = new DiscoverableSubscribingDriverFactory("Modbus");
+ var deploymentId = SeedDeploymentWithEquipmentTags(db, RevA,
+ (Equip: "EQ-1", Driver: "d1", FullName: "40001", Folder: (string?)null, Name: "speed"));
+
+ var coordinator = CreateTestProbe();
+ var publish = CreateTestProbe();
+ var vtHost = CreateTestProbe();
+
+ var actor = Sys.ActorOf(DriverHostActor.Props(
+ db, TestNode, coordinator.Ref,
+ driverFactory: factory,
+ localRoles: new HashSet { "driver" },
+ opcUaPublishActor: publish.Ref,
+ virtualTagHostOverride: vtHost.Ref));
+
+ actor.Tell(new DispatchDeployment(deploymentId, RevA, CorrelationId.NewId()));
+ coordinator.ExpectMsg(Timeout).Outcome.ShouldBe(ApplyAckOutcome.Applied);
+ publish.ExpectMsg(Timeout);
+
+ // The child connects and runs its single (Once) post-connect discovery pass, which the host grafts
+ // under EQ-1 — this POPULATES the per-equipment cache (_discoveredByDriver[d1] = { EQ-1: plan }).
+ publish.FishForMessage(
+ m => m.EquipmentRootNodeId == "EQ-1", Timeout);
+ AwaitAssert(() => factory.DiscoverCount.ShouldBe(1), duration: Timeout);
+
+ // Redeploy: REBIND d1 from EQ-1 → EQ-2 (same FullName; DriverConfig "{}" unchanged so ReconcileDrivers
+ // does NOT restart the child). The re-inject tail drops the stale EQ-1-scoped cache entry.
+ var deploymentId2 = SeedDeploymentWithEquipmentTags(db, RevB,
+ (Equip: "EQ-2", Driver: "d1", FullName: "40001", Folder: (string?)null, Name: "speed"));
+ actor.Tell(new DispatchDeployment(deploymentId2, RevB, CorrelationId.NewId()));
+ coordinator.ExpectMsg(Timeout).Outcome.ShouldBe(ApplyAckOutcome.Applied);
+
+ // The drop must SEND DriverInstanceActor.TriggerRediscovery to d1's (still-Connected) child, which
+ // re-runs discovery: DiscoverCount advances past the single connect pass — the observable proof the
+ // trigger reached the child. (Pre-task: no trigger ⇒ Once already settled, child never reconnects ⇒
+ // DiscoverCount stays 1 ⇒ this fails.)
+ AwaitAssert(() => factory.DiscoverCount.ShouldBeGreaterThan(1), duration: TimeSpan.FromSeconds(10));
+
+ // ... and the re-triggered pass re-grafts the FixedTree under the NEW equipment EQ-2 (the host resolves
+ // d1 → EQ-2 against the new _lastComposition).
+ publish.FishForMessage(
+ m => m.EquipmentRootNodeId == "EQ-2", Timeout);
+ }
+
/// Spawns the host with the subscribing driver factory + a publish probe, dispatches the
/// deployment, and waits for the Applied ACK so the apply (and thus _lastComposition + the live
/// child + the initial SubscribeBulk pass) has completed before the test injects discovered nodes. A
@@ -628,4 +690,87 @@ public sealed class DriverHostActorDiscoveryTests : RuntimeActorTestBase
///
public IReadOnlyCollection SupportedTypes => new[] { _supportedType };
}
+
+ /// Factory producing a single shared for the supported
+ /// type — a real (non-stubbed) child that exposes ,
+ /// so the host's post-connect discovery loop populates the discovered-node cache AND a
+ /// re-runs discovery (the seam the rebind re-trigger
+ /// test asserts through). Exposes the driver's pass count so a test can observe the trigger landing.
+ private sealed class DiscoverableSubscribingDriverFactory : IDriverFactory
+ {
+ private readonly string _supportedType;
+ private DiscoverableSubscribingDriver? _driver;
+ public DiscoverableSubscribingDriverFactory(string supportedType) { _supportedType = supportedType; }
+
+ /// Number of DiscoverAsync passes the child has driven (advances on every
+ /// connect-time pass and every -driven pass).
+ public int DiscoverCount => _driver?.DiscoverCount ?? 0;
+
+ ///
+ public IDriver? TryCreate(string driverType, string driverInstanceId, string driverConfigJson) =>
+ string.Equals(driverType, _supportedType, StringComparison.Ordinal)
+ ? _driver ??= new DiscoverableSubscribingDriver(driverInstanceId)
+ : null;
+
+ ///
+ public IReadOnlyCollection SupportedTypes => new[] { _supportedType };
+ }
+
+ /// A that is BOTH (so the host's subscribe
+ /// path is exercised) and with policy
+ /// — exactly one post-connect pass, re-runnable by . Each
+ /// pass streams an ever-growing FixedTree (pass N → N nodes, refs "ft-ref-1".."ft-ref-N", none shadowing the
+ /// authored "40001"), so a re-triggered pass yields a grown set the host re-applies — and the public
+ /// makes the trigger observable at the host level. Re-implements
+ /// (the base hardcodes "stub-driver-1") so the
+ /// spawned child reports the SPEC's id — otherwise its auto-sent
+ /// would carry the wrong driver id and resolve no equipment.
+ private sealed class DiscoverableSubscribingDriver : StubDriver, IDriver, ISubscribable, ITagDiscovery
+ {
+ private int _passCount;
+ private readonly string _driverInstanceId;
+ private readonly StubHandle _handle = new();
+
+ public DiscoverableSubscribingDriver(string driverInstanceId) => _driverInstanceId = driverInstanceId;
+
+ /// The spec's driver instance id (re-mapped from the base "stub-driver-1").
+ public new string DriverInstanceId => _driverInstanceId;
+
+ /// Single post-connect pass per (re)kick — re-runnable by TriggerRediscovery.
+ public DiscoveryRediscoverPolicy RediscoverPolicy => DiscoveryRediscoverPolicy.Once;
+
+ /// Number of DiscoverAsync passes driven so far.
+ public int DiscoverCount => Volatile.Read(ref _passCount);
+
+ /// Never raised (the test asserts on discovery + materialise, not data changes); explicit
+ /// empty accessors satisfy the interface without a never-used backing field (no CS0067).
+ public event EventHandler? OnDataChange { add { } remove { } }
+
+ ///
+ public Task SubscribeAsync(
+ IReadOnlyList fullReferences, TimeSpan publishingInterval, CancellationToken cancellationToken)
+ => Task.FromResult(_handle);
+
+ ///
+ public Task UnsubscribeAsync(ISubscriptionHandle handle, CancellationToken cancellationToken)
+ => Task.CompletedTask;
+
+ /// Streams an ever-growing FixedTree (pass N → N nodes).
+ public Task DiscoverAsync(IAddressSpaceBuilder builder, CancellationToken cancellationToken)
+ {
+ var pass = Interlocked.Increment(ref _passCount);
+ var fixedTree = builder.Folder("FixedTree", "FixedTree");
+ for (var i = 0; i < pass; i++)
+ {
+ fixedTree.Variable($"v{i}", $"v{i}", new DriverAttributeInfo(
+ FullName: $"ft-ref-{i + 1}",
+ DriverDataType: DriverDataType.Float64,
+ IsArray: false,
+ ArrayDim: null,
+ SecurityClass: SecurityClassification.ViewOnly,
+ IsHistorized: false));
+ }
+ return Task.CompletedTask;
+ }
+ }
}