Merge branch 'master' into b626-626

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Observability/OtOpcUaTelemetry.cs

@@ -76,6 +76,16 @@ public static class OtOpcUaTelemetry
     /// </summary>
     public const string PollOverrunDriverInstanceTag = "driver_instance";
 
+    /// <summary>
+    /// Session/publish-level events of an OPC UA Client driver instance (#276): the operator's view of a
+    /// flapping upstream. Tagged <see cref="PollOverrunDriverInstanceTag"/> (<c>driver_instance</c>) +
+    /// <c>event</c> = <c>publish_response|notification|data_change|bad_status_value|publish_error|
+    /// keepalive_miss|reconnect_attempt|reconnect_success|reconnect_exhausted</c>.
+    /// </summary>
+    public static readonly Counter<long> OpcUaClientEvents =
+        Meter.CreateCounter<long>("otopcua.driver.opcuaclient.events", unit: "{event}",
+            description: "OPC UA Client driver session/publish events (event=publish_response|notification|data_change|bad_status_value|publish_error|keepalive_miss|reconnect_attempt|reconnect_success|reconnect_exhausted).");
+
     // ---------------- VirtualTag / ScriptedAlarm engines ----------------
 
     public static readonly Counter<long> VirtualTagEval =

src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/IHistoryProvider.cs

@@ -132,6 +132,14 @@ public sealed record HistoryReadResult(
     byte[]? ContinuationPoint);
 
 /// <summary>Aggregate function for processed history reads. Mirrors OPC UA Part 13 standard aggregates.</summary>
+/// <remarks>
+///     The first five members are the original set every historian backend serves. The remainder (#285) are
+///     the further standard Part 13 aggregates a server-side HistoryRead can forward to a backend that
+///     supports them (the OPC UA Client driver forwards all of them upstream). A backend that cannot serve a
+///     member must throw <see cref="HistoryAggregateNotSupportedException"/> — the server maps that to
+///     <c>BadAggregateNotSupported</c> rather than a generic failure. <b>Append only</b>: the numeric values
+///     are not persisted, but every <c>switch</c> over this enum must keep a total default.
+/// </remarks>
 public enum HistoryAggregateType
 {
     Average,
@@ -139,6 +147,42 @@ public enum HistoryAggregateType
     Maximum,
     Total,
     Count,
+    Interpolative,
+    TimeAverage,
+    Start,
+    End,
+    Delta,
+    Range,
+    MinimumActualTime,
+    MaximumActualTime,
+    StartBound,
+    EndBound,
+    DeltaBounds,
+    DurationGood,
+    DurationBad,
+    PercentGood,
+    PercentBad,
+    WorstQuality,
+    NumberOfTransitions,
+    AnnotationCount,
+    StandardDeviationPopulation,
+    VariancePopulation,
+}
+
+/// <summary>
+///     Thrown by a history backend when it cannot serve the requested <see cref="HistoryAggregateType"/>.
+///     The Server HistoryRead path translates it to <c>BadAggregateNotSupported</c> for that node only.
+/// </summary>
+public sealed class HistoryAggregateNotSupportedException : NotSupportedException
+{
+    /// <summary>The aggregate the backend could not serve.</summary>
+    public HistoryAggregateType Aggregate { get; }
+
+    /// <summary>Creates the exception for <paramref name="aggregate"/>.</summary>
+    /// <param name="aggregate">The unsupported aggregate.</param>
+    public HistoryAggregateNotSupportedException(HistoryAggregateType aggregate)
+        : base($"The historian backend does not support the {aggregate} aggregate.")
+        => Aggregate = aggregate;
 }
 
 /// <summary>