diff --git a/docs/Historian.md b/docs/Historian.md
index 0e66252c..f4c1d8e4 100644
--- a/docs/Historian.md
+++ b/docs/Historian.md
@@ -673,6 +673,17 @@ modification time and the Part 11 `HistoryUpdateType`. A HistoryReadRaw with `Is
so a change and its trail row commit or roll back together. QuestDB has no multi-table transaction, so the trail row is written **before**
the change: a crash (or failed sample INSERT) in between leaves an **orphan trail row** describing a change that never landed — never a
change without its trail row. Treat a QuestDB trail entry whose sample still shows the prior value as such an orphan.
+ A failed sample write after its trail rows landed logs a **Warning** naming the tag, the row count and the time range, so the orphan
+ can be found.
+- **Rolling upgrade (SqlServer).** The v2 schema is applied by the first node that upgrades. Until its peer is upgraded too, that
+ not-yet-upgraded node still runs the old build, whose HistoryUpdates write **no trail rows** — silent gaps in the audit trail. Upgrade both
+ nodes of a pair together (stop, upgrade, start both); modifications made by an old-build node in the window are never recorded.
+- **Paging vs a concurrent HistoryUpdate (SqlServer).** `ModifiedId` is an `IDENTITY`, which orders by allocation, not by commit. A modified
+ read paging at the same moment a HistoryUpdate commits a modification of the **same source timestamp** can have already passed that
+ row's id and so never see it on this pass (a fresh read does). The cursor is exact for a quiescent trail, not a snapshot guarantee.
+- **QuestDB `ModifiedId` across nodes.** Ids are UTC ticks bumped past the last one issued by that process, so a pair's ids interleave by
+ each node's **wall clock**. Same-source-time modifications made on two nodes order by their clocks (clock skew can reorder them);
+ within one node the order is strict.
- **Retention.** The trail ages out on the same **source-time** cutoff as the samples it describes: `SqlServer` purges `hist.SampleModified`
per tag alongside `hist.Sample`; QuestDB puts the same TTL on `{p}sample_modified`.
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/HistoryModifiedContracts.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/HistoryModifiedContracts.cs
index aa1c03f7..d3ad6b4c 100644
--- a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/HistoryModifiedContracts.cs
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/HistoryModifiedContracts.cs
@@ -51,12 +51,17 @@ public enum HistoryModificationType : byte
/// The kind of modification.
/// The principal that made it.
/// The backend's ordering key within one source timestamp (paging cursor).
+///
+/// The modified sample's source time as stored on the trail row — the paging cursor's time component. Explicit
+/// because an insert's has no prior value and so cannot be relied on to carry it.
+///
public sealed record HistoryModifiedValue(
DataValueSnapshot Value,
DateTime ModificationTimeUtc,
HistoryModificationType UpdateType,
string UserName,
- long ModifiedId);
+ long ModifiedId,
+ DateTime SourceTimeUtc);
/// Resume position for a paged modified-value read: strictly after (or before, reversed) this key.
/// The last returned modification's source time.
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataSource.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataSource.cs
index 95eb33fb..3f6b939b 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataSource.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataSource.cs
@@ -221,7 +221,7 @@ public sealed class QuestDbHistorianDataSource : IHistorianDataSource
values.Add(new HistoryModifiedValue(prior, modifiedAt,
(HistoryModificationType)QuestDbConnection.ReadKind(reader, 9),
reader.IsDBNull(10) ? string.Empty : reader.GetString(10),
- reader.GetInt64(7)));
+ reader.GetInt64(7), sourceTime));
}
}
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataUpdater.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataUpdater.cs
index 91cdf513..91b060ed 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataUpdater.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataUpdater.cs
@@ -155,7 +155,8 @@ internal sealed class QuestDbHistorianDataUpdater : IHistorianDataUpdater
// tombstone without its trail row.
await WriteTrailAsync(tag, HistoryModificationType.Delete,
priors.Select(r => (r.TimeUtc, (LiveRow?)r)).ToList(), context, ct).ConfigureAwait(false);
- await WriteTombstonesAsync(tag, page, ct).ConfigureAwait(false);
+ await AfterTrailAsync(tag, page[0], page[^1], page.Count,
+ () => WriteTombstonesAsync(tag, page, ct)).ConfigureAwait(false);
// The wait between pages is required: without it the next page could re-read rows just tombstoned.
await _wal.WaitAsync(_conn.SampleTable, ct).ConfigureAwait(false);
total += page.Count;
@@ -197,7 +198,9 @@ internal sealed class QuestDbHistorianDataUpdater : IHistorianDataUpdater
// Trail BEFORE the change (see the class remarks).
await WriteTrailAsync(tag, HistoryModificationType.Delete,
chunk.Select(t => (live[t].TimeUtc, (LiveRow?)live[t])).ToList(), context, ct).ConfigureAwait(false);
- await WriteTombstonesAsync(tag, chunk.Select(t => new DateTime(t, DateTimeKind.Utc)).ToList(), ct).ConfigureAwait(false);
+ var chunkTimes = chunk.Select(t => new DateTime(t, DateTimeKind.Utc)).ToList();
+ await AfterTrailAsync(tag, chunkTimes[0], chunkTimes[^1], chunkTimes.Count,
+ () => WriteTombstonesAsync(tag, chunkTimes, ct)).ConfigureAwait(false);
}
if (toDelete.Count > 0) await _wal.WaitAsync(_conn.SampleTable, ct).ConfigureAwait(false);
deleted.UnionWith(toDelete);
@@ -231,7 +234,8 @@ internal sealed class QuestDbHistorianDataUpdater : IHistorianDataUpdater
// Trail BEFORE the change (see the class remarks).
await WriteTrailAsync(tag, ToModificationType(mode), trail, context, ct).ConfigureAwait(false);
foreach (var chunk in toWrite.Chunk(BatchSize))
- await WriteRowsAsync(tag, chunk, ct).ConfigureAwait(false);
+ await AfterTrailAsync(tag, chunk[0].TimeUtc, chunk[^1].TimeUtc, chunk.Length,
+ () => WriteRowsAsync(tag, chunk, ct)).ConfigureAwait(false);
if (toWrite.Count > 0) await _wal.WaitAsync(_conn.SampleTable, ct).ConfigureAwait(false);
return outcome;
}
@@ -367,6 +371,27 @@ internal sealed class QuestDbHistorianDataUpdater : IHistorianDataUpdater
await _wal.WaitAsync(_conn.SampleModifiedTable, ct).ConfigureAwait(false);
}
+ ///
+ /// Runs the sample write that follows an already-written trail batch. QuestDB has no multi-table transaction, so a
+ /// failure here leaves an ORPHAN trail row (a recorded modification that never landed); it is logged with the tag
+ /// and time range so an operator can reconcile it, then rethrown unchanged.
+ ///
+ private async Task AfterTrailAsync(string tag, DateTime from, DateTime to, int count, Func write)
+ {
+ try
+ {
+ await write().ConfigureAwait(false);
+ }
+ catch (Exception ex)
+ {
+ _log.LogWarning(ex,
+ "QuestDB sample write failed AFTER its {Table} trail rows were written; {Count} orphan audit row(s) for tag {Tag} " +
+ "in [{From:O}, {To:O}] describe a modification that did not land.",
+ _conn.SampleModifiedTable, count, tag, from, to);
+ throw;
+ }
+ }
+
private Task WriteRowsAsync(string tag, IReadOnlyList rows, CancellationToken ct) =>
InsertAsync(rows.Count, ct, (cmd, i) =>
{
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs
index 530192c7..99182de6 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs
@@ -212,7 +212,7 @@ public sealed class SqlServerHistorianDataSource : IHistorianDataSource
}
values.Add(new HistoryModifiedValue(
- prior, modifiedAt, (HistoryModificationType)reader.GetByte(9), reader.GetString(10), reader.GetInt64(7)));
+ prior, modifiedAt, (HistoryModificationType)reader.GetByte(9), reader.GetString(10), reader.GetInt64(7), sourceTime));
}
}
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
index 33d623f7..0c2780b8 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
@@ -6218,7 +6218,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
{
var last = page.Values[^1];
outboundCp = _historyContinuationStore.Save(session, new HistoryContinuationState(
- tagname, last.Value.SourceTimestampUtc ?? DateTime.MinValue, endUtc, 0, numValuesPerNode,
+ tagname, last.SourceTimeUtc, endUtc, 0, numValuesPerNode,
HistoryCursorKind.Modified, last.ModifiedId, startUtc));
}
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/HistoryUpdateOverTheWireTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/HistoryUpdateOverTheWireTests.cs
index 76e6883f..16f9ccc4 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/HistoryUpdateOverTheWireTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests/HistoryUpdateOverTheWireTests.cs
@@ -313,7 +313,7 @@ public sealed class HistoryUpdateOverTheWireTests
private void Record(DateTime t, double? prior, HistoryModificationType type, HistoryUpdateContext who) =>
_trail.Add(new HistoryModifiedValue(
new DataValueSnapshot(prior, prior is null ? StatusCodes.BadNoData : StatusCodes.Good, t, t),
- DateTime.UtcNow, type, who.Principal, _trail.Count + 1));
+ DateTime.UtcNow, type, who.Principal, _trail.Count + 1, t));
public int UpdateCalls => Volatile.Read(ref _updateCalls);
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerAclEnforcementTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerAclEnforcementTests.cs
index 65ed1720..9dedcab8 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerAclEnforcementTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerAclEnforcementTests.cs
@@ -101,7 +101,7 @@ public sealed class NodeManagerAclEnforcementTests : IDisposable
try
{
var nm = server.NodeManager!;
- nm.HistorianDataSource = NullHistorianDataSource.Instance;
+ nm.HistorianDataSource = new OneModificationTrail();
var nodeId = Historized(nm, "Plant/Modbus/dev1/Speed");
nm.Authorizer = Authorizer(enabled: true, GrantOn(NodePermissions.Read));
@@ -110,8 +110,14 @@ public sealed class NodeManagerAclEnforcementTests : IDisposable
deniedResults[0].StatusCode.Code.ShouldBe(StatusCodes.BadUserAccessDenied);
nm.Authorizer = Authorizer(enabled: true, GrantOn(NodePermissions.HistoryRead));
- var (_, allowedErrors) = ReadRaw(nm, Identity(), modified: true, nodeId);
- allowedErrors[0].StatusCode.Code.ShouldBe(StatusCodes.BadHistoryOperationUnsupported);
+ var (allowedResults, allowedErrors) = ReadRaw(nm, Identity(), modified: true, nodeId);
+ // A real trail entry must come back: Null's BadHistoryOperationUnsupported is also what the SDK pre-seeds,
+ // so asserting it would pass even if the grant never reached the modified branch.
+ allowedErrors[0].StatusCode.Code.ShouldBe(StatusCodes.Good);
+ allowedResults[0].StatusCode.Code.ShouldBe(StatusCodes.Good);
+ var data = ExtensionObject.ToEncodeable(allowedResults[0].HistoryData).ShouldBeOfType();
+ data.DataValues.Count.ShouldBe(1);
+ data.ModificationInfos[0].UserName.ShouldBe("alice");
}
finally { await host.DisposeAsync(); }
}
@@ -327,6 +333,32 @@ public sealed class NodeManagerAclEnforcementTests : IDisposable
}
}
+ /// A backend whose modified-value trail holds exactly one entry; every other read is empty.
+ private sealed class OneModificationTrail : IHistorianDataSource
+ {
+ public Task ReadModifiedAsync(
+ string fullReference, DateTime startUtc, DateTime endUtc, uint maxValues, HistoryModifiedCursor? resumeAfter,
+ CancellationToken cancellationToken)
+ {
+ var t = DateTime.UtcNow.AddMinutes(-5);
+ var prior = new DataValueSnapshot(1.5, StatusCodes.Good, t, t);
+ return Task.FromResult(new HistoryModifiedReadResult(
+ [new HistoryModifiedValue(prior, DateTime.UtcNow, HistoryModificationType.Replace, "alice", 1, t)], false));
+ }
+
+ public Task ReadRawAsync(string r, DateTime s, DateTime e, uint m, CancellationToken ct) =>
+ NullHistorianDataSource.Instance.ReadRawAsync(r, s, e, m, ct);
+ public Task ReadProcessedAsync(
+ string r, DateTime s, DateTime e, TimeSpan i, HistoryAggregateType a, CancellationToken ct) =>
+ NullHistorianDataSource.Instance.ReadProcessedAsync(r, s, e, i, a, ct);
+ public Task ReadAtTimeAsync(string r, IReadOnlyList t, CancellationToken ct) =>
+ NullHistorianDataSource.Instance.ReadAtTimeAsync(r, t, ct);
+ public Task ReadEventsAsync(string? n, DateTime s, DateTime e, int m, CancellationToken ct) =>
+ NullHistorianDataSource.Instance.ReadEventsAsync(n, s, e, m, ct);
+ public HistorianHealthSnapshot GetHealthSnapshot() => NullHistorianDataSource.Instance.GetHealthSnapshot();
+ public void Dispose() { }
+ }
+
private static NodeId Historized(OtOpcUaNodeManager nm, string rawPath)
{
nm.EnsureVariable(rawPath, parentFolderNodeId: null, displayName: rawPath, dataType: "Float",
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadModifiedTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadModifiedTests.cs
index dd2ee07c..fc12cc7f 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadModifiedTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadModifiedTests.cs
@@ -105,6 +105,56 @@ public sealed class NodeManagerHistoryReadModifiedTests : IDisposable
await host.DisposeAsync();
}
+ [Fact]
+ public async Task An_end_only_modified_read_pages_backward_from_the_end()
+ {
+ var trail = Enumerable.Range(1, 9).Select(i => Mod(i, seconds: i, prior: i, HistoryModificationType.Update, "u", Epoch)).ToList();
+ var (host, nm, node, src) = await SetupAsync(trail);
+
+ // StartTime unset + EndTime set + a cap = "the newest N, walking backward".
+ Drain(nm, node, DateTime.MinValue, Epoch.AddHours(1), max: 4).ShouldBe(src.Ordered(reverse: true).Select(m => m.ModifiedId));
+ src.LastStart.ShouldBe(Epoch.AddHours(1));
+ src.LastEnd.ShouldBe(new DateTime(0, DateTimeKind.Utc));
+ await host.DisposeAsync();
+ }
+
+ [Fact]
+ public async Task A_reverse_resume_hands_the_backend_the_last_returned_source_time_and_id()
+ {
+ // Ids 3 and 4 share a source time; page 1 (reverse, cap 3) ends on id 4, then resumes mid-run.
+ var trail = new List
+ {
+ Mod(1, 1, 1, HistoryModificationType.Update, "u", Epoch), Mod(2, 2, 2, HistoryModificationType.Update, "u", Epoch),
+ Mod(3, 3, 3, HistoryModificationType.Update, "u", Epoch), Mod(4, 3, 4, HistoryModificationType.Update, "u", Epoch),
+ Mod(5, 5, 5, HistoryModificationType.Update, "u", Epoch), Mod(6, 6, 6, HistoryModificationType.Update, "u", Epoch),
+ };
+ var (host, nm, node, src) = await SetupAsync(trail);
+
+ var p1 = Read(nm, node, Epoch.AddHours(1), Epoch.AddSeconds(-1), max: 3, cp: null);
+ p1.Ids.ShouldBe([6, 5, 4]);
+ p1.Cp.ShouldNotBeNull();
+ var p2 = Read(nm, node, Epoch.AddHours(1), Epoch.AddSeconds(-1), max: 3, cp: p1.Cp);
+ src.LastCursor.ShouldBe(new HistoryModifiedCursor(Epoch.AddSeconds(3), 4));
+ p2.Ids.ShouldBe([3, 2, 1]);
+ await host.DisposeAsync();
+ }
+
+ [Fact]
+ public async Task The_resume_cursor_uses_the_explicit_source_time_even_when_the_prior_value_carries_none()
+ {
+ // Inserts have no prior value; their snapshot has no source timestamp. The cursor must not fall back to MinValue.
+ var trail = Enumerable.Range(1, 6).Select(i => new HistoryModifiedValue(
+ new DataValueSnapshot(null, StatusCodes.BadNoData, null, Epoch), Epoch, HistoryModificationType.Insert, "u", i,
+ Epoch.AddSeconds(i))).ToList();
+ var (host, nm, node, src) = await SetupAsync(trail);
+
+ var p1 = Read(nm, node, Epoch, Epoch.AddHours(1), max: 3, cp: null);
+ p1.Cp.ShouldNotBeNull();
+ Read(nm, node, Epoch, Epoch.AddHours(1), max: 3, cp: p1.Cp);
+ src.LastCursor.ShouldBe(new HistoryModifiedCursor(Epoch.AddSeconds(3), 3));
+ await host.DisposeAsync();
+ }
+
[Fact]
public async Task An_open_ended_forward_modified_read_pages_to_the_end()
{
@@ -172,7 +222,7 @@ public sealed class NodeManagerHistoryReadModifiedTests : IDisposable
var value = prior is null
? new DataValueSnapshot(null, StatusCodes.BadNoData, t, modifiedAt)
: new DataValueSnapshot(prior.Value, StatusCodes.Good, t, t);
- return new HistoryModifiedValue(value, modifiedAt, type, user, id);
+ return new HistoryModifiedValue(value, modifiedAt, type, user, id, t);
}
private static List Drain(OtOpcUaNodeManager nm, NodeId node, DateTime start, DateTime end, uint max)
@@ -258,8 +308,8 @@ public sealed class NodeManagerHistoryReadModifiedTests : IDisposable
public static long IdOf(DataValue v) => v.ServerTimestamp.Ticks - Epoch.Ticks;
public IEnumerable Ordered(bool reverse) => reverse
- ? trail.OrderByDescending(m => m.Value.SourceTimestampUtc).ThenByDescending(m => m.ModifiedId)
- : trail.OrderBy(m => m.Value.SourceTimestampUtc).ThenBy(m => m.ModifiedId);
+ ? trail.OrderByDescending(m => m.SourceTimeUtc).ThenByDescending(m => m.ModifiedId)
+ : trail.OrderBy(m => m.SourceTimeUtc).ThenBy(m => m.ModifiedId);
public async Task ReadModifiedAsync(
string fullReference, DateTime startUtc, DateTime endUtc, uint maxValues, HistoryModifiedCursor? resumeAfter,
@@ -273,7 +323,7 @@ public sealed class NodeManagerHistoryReadModifiedTests : IDisposable
var (lo, hi) = reverse ? (endUtc, startUtc) : (startUtc, endUtc);
var rows = Ordered(reverse).Where(m =>
{
- var t = m.Value.SourceTimestampUtc!.Value;
+ var t = m.SourceTimeUtc;
var inWindow = startUtc == endUtc ? t == lo : reverse ? t > lo && t <= hi : t >= lo && t < hi;
if (!inWindow) return false;
if (resumeAfter is null) return true;