refactor(opcuaserver): async-ify ServeNode + Processed/AtTime HistoryRead internals, thread cancellation (03/S3)

archreview/plans/R2-08-ldap-historyread-async-plan.md.tasks.json

@@ -9,7 +9,7 @@
     { "id": "R2-08-T6", "subject": "Outage-sim integration test (real library, unroutable host, via internal HandleImpersonation) + SDK m_eventLock contract doc + docs/security.md", "status": "completed", "blockedBy": ["R2-08-T4"] },
     { "id": "R2-08-T7", "subject": "S3 sequential-serving repro test (RED): MaxObservedConcurrency >= 2 on an 8-node Raw batch — fails on current code", "status": "completed", "blockedBy": [] },
     { "id": "R2-08-T8", "subject": "ServerHistorianOptions: HistoryReadBatchParallelism/MaxConcurrentHistoryReadBatches/HistoryReadDeadline + Validate warnings + node-manager properties + hosted-service wiring", "status": "completed", "blockedBy": [] },
-    { "id": "R2-08-T9", "subject": "Async-ify ServeNode + Processed/AtTime arms (ct threading, OCE=>BadTimeout, behavior-neutral)", "status": "pending", "blockedBy": ["R2-08-T7", "R2-08-T8"] },
+    { "id": "R2-08-T9", "subject": "Async-ify ServeNode + Processed/AtTime arms (ct threading, OCE=>BadTimeout, behavior-neutral)", "status": "completed", "blockedBy": ["R2-08-T7", "R2-08-T8"] },
     { "id": "R2-08-T10", "subject": "Async-ify ServeRawPaged (page read + tie-cluster over-fetch) + extract ServeEventsAsync", "status": "pending", "blockedBy": ["R2-08-T9"] },
     { "id": "R2-08-T11", "subject": "RunBounded fan-out in all four HistoryRead arms, single bridge per arm (turns T7 green) + upper-bound + isolation tests", "status": "pending", "blockedBy": ["R2-08-T9", "R2-08-T10"] },
     { "id": "R2-08-T12", "subject": "Per-request HistoryRead deadline CTS — hung backend surfaces BadTimeout per node", "status": "pending", "blockedBy": ["R2-08-T11"] },

src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs

@@ -1861,13 +1861,14 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
             // and the single-shot backend returns every bucket in one read, so there is no "full page ⇒
             // maybe more" signal to page on. Returning the complete aggregate result with a null CP is
             // spec-conformant (OPC UA Part 11 lets a server return all available data in one response).
-            ServeNode(handle, results, errors, (source, tagname) => source.ReadProcessedAsync(
+            // Interim: still bridged sequentially per node (bounded fan-out lands in a later slice).
+            ServeNodeAsync(handle, results, errors, (source, tagname, token) => source.ReadProcessedAsync(
                 tagname,
                 details.StartTime,
                 details.EndTime,
                 interval,
                 aggregate.Value,
-                CancellationToken.None));
+                token), CancellationToken.None).GetAwaiter().GetResult();
         }
     }
 
@@ -1886,10 +1887,11 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         var timestamps = details.ReqTimes?.ToList() ?? new List<DateTime>();
         foreach (var handle in nodesToProcess)
         {
-            ServeNode(handle, results, errors, (source, tagname) => source.ReadAtTimeAsync(
+            // Interim: still bridged sequentially per node (bounded fan-out lands in a later slice).
+            ServeNodeAsync(handle, results, errors, (source, tagname, token) => source.ReadAtTimeAsync(
                 tagname,
                 timestamps,
-                CancellationToken.None));
+                token), CancellationToken.None).GetAwaiter().GetResult();
         }
     }
 
@@ -2061,11 +2063,12 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
     /// <param name="errors">The service-level errors list to fill at <c>handle.Index</c>.</param>
     /// <param name="read">Invokes the resolved data-source read with the resolved tagname; only called
     /// once the tagname is confirmed present.</param>
-    private void ServeNode(
+    private async Task ServeNodeAsync(
         NodeHandle handle,
         IList<SdkHistoryReadResult> results,
         IList<ServiceResult> errors,
-        Func<IHistorianDataSource, string, Task<HistorianRead>> read)
+        Func<IHistorianDataSource, string, CancellationToken, Task<HistorianRead>> read,
+        CancellationToken ct)
     {
         var idString = handle.NodeId.Identifier?.ToString();
         if (idString is null || !TryGetHistorizedTagname(idString, out var tagname))
@@ -2078,9 +2081,9 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
 
         try
         {
-            // HistoryRead is NOT invoked under the node-manager Lock (unlike OnWriteValue), so blocking
+            // HistoryRead is NOT invoked under the node-manager Lock (unlike OnWriteValue), so awaiting
-            // on the async source here is safe and won't freeze the address space.
+            // the async source here is safe and won't freeze the address space.
-            var sourceResult = read(HistorianDataSource, tagname!).GetAwaiter().GetResult();
+            var sourceResult = await read(HistorianDataSource, tagname!, ct).ConfigureAwait(false);
             var historyData = ToHistoryData(sourceResult);
 
             results[handle.Index] = new SdkHistoryReadResult
@@ -2095,13 +2098,20 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
             };
             errors[handle.Index] = ServiceResult.Good;
         }
+        catch (OperationCanceledException)
+        {
+            // The per-request deadline elapsed while this node was in flight — surface BadTimeout for
+            // THIS node only (a spec-conformant history-read status), ahead of the generic catch.
+            errors[handle.Index] = StatusCodes.BadTimeout;
+            results[handle.Index] = new SdkHistoryReadResult { StatusCode = StatusCodes.BadTimeout };
+        }
         catch (Exception ex)
         {
-            // One node's backend failure (throw / timeout / cancellation) must not throw out of the
+            // One node's backend failure (throw / timeout) must not throw out of the batch — surface a
-            // batch — surface a Bad status for THIS node only. This CustomNodeManager2 carries no
+            // Bad status for THIS node only. This CustomNodeManager2 carries no ILogger (see
-            // ILogger (see ReportConditionEvent), so log through the SDK's static trace rather than
+            // ReportConditionEvent), so log through the SDK's static trace rather than swallowing silently.
-            // swallowing silently. Utils.LogError is [Obsolete] in 1.5.378 (favours an ITelemetryContext
+            // Utils.LogError is [Obsolete] in 1.5.378 (favours an ITelemetryContext this manager doesn't
-            // this manager doesn't wire) — suppress the deprecation, matching the existing pattern.
+            // wire) — suppress the deprecation, matching the existing pattern.
 #pragma warning disable CS0618 // Type or member is obsolete
             Utils.LogError(ex, "OtOpcUaNodeManager: HistoryRead failed for node {0}", handle.NodeId);
 #pragma warning restore CS0618