IL walk of the native wrapper:
HistorianAccess.AddRevisionValuesBegin (private, token 0x06006175)
-> CClientCommon.AddNonStreamValuesBegin
-> CClient.AddNonStreamValuesBegin (8-instr overload)
-> CClient.TransactionBegin
-> CHistStorageConnection.StartTransaction (token 0x06001FDD)
-> CStorageEngineConsoleClient.StartTransaction
CStorageEngineConsoleClient is built on STransactPipeClient2 +
SCrtMemFile — a shared-memory + named-pipe transport to
aaStorageEngine.exe, completely separate from WCF.
The WCF ITransactionServiceContract2.AddNonStreamValuesBegin2 op is a
server-side relay that requires a pre-existing storage-engine pipe
session for the client. Without that pipe session, the WCF relay returns
UnknownClient (51) — and there's no way to establish the pipe session
via WCF.
D2 is unimplementable as a pure-managed-WCF SDK. The native wrapper
itself depends on the C++ shared-memory channel; replicating that from
managed code would require implementing the storage-engine pipe
protocol, which is a major undertaking and out of scope.
The ITransactionServiceContract2 declaration in our contracts file
stays as documentation; no public API or orchestrator added.
HistorianWcfRevisionOrchestrator remains as an internal probe /
regression check — re-run the probe test if anyone believes the
architecture has changed.
178/178 tests still pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Tested hypothesis (1) from the plan: add RTag2(CM_EVENT tag id) to the
priming chain before AddNonStreamValuesBegin2.
Result:
- RTag2 itself succeeds: returns 25-byte response
(01000000000100000001EE39C30EDCDC010100000000000000), no error buffer.
- But AddNonStreamValuesBegin2 still fails with the same
04 33 00 00 00 (UnknownClient = 51) for all four handle formats.
So RTag2 on /Hist isn't the cross-service registration trigger we need
for /Trx. Plan doc updated with the result + next-session ordered
probes (try IStorageServiceContract, then IL walk CClientCommon,
then server-side decompile as last resort).
Probe orchestrator now also performs the RTag2 step so the test gives
one-shot diagnostic visibility of both calls.
178/178 tests pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Implemented HistorianWcfRevisionOrchestrator that talks WCF directly
to /Trx, bypassing the native wrapper entirely. Probes
AddNonStreamValuesBegin2 against the live local Historian and surfaces
what the server returns. Internal-only API; no public surface added —
the path isn't viable yet.
Findings (live test against localhost):
- ✅ The wire path is reachable. After moving from V1 (uint handle, no
errorBuffer) to V2 (string handle GUID, out errorBuffer), the server
recognizes the call (no ContractFilter mismatch, no exception).
- ✅ Server processes the call and returns a structured 5-byte error
buffer: 04 33 00 00 00 = type 4 (CustomError) + code 51
(UnknownClient).
- ❌ Tried four handle formats (contextKey upper/lower, storageSessionId
upper, ClientHandle as decimal string) — all return the same
UnknownClient.
- ❌ Adding the full priming chain (Stat.GetV ×2, Stat.GETHI ×2, UpdC3,
6× Stat.GetSystemParameter, AllowRenameTags, Trx.GetV, Stat.GetV,
Retr.GetV) — same result.
ITransactionServiceContract2 has no Validate/Register/Open op of its
own. The client-with-Trx registration must happen via some cross-
service side effect we haven't isolated.
Important takeaway: the wire-format mismatch is solved (contract method
names + parameter shapes match what the server expects). The remaining
gap is a single missing initialization step. Documented in
docs/plans/revision-write-path.md as concrete next-session steps.
178/178 tests pass (one new probe test added). Probe is gated on
HISTORIAN_HOST=localhost.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Direct HistorianAccess.AddNonStreamedValue (the 4-param overload that
bypasses HistorianDataValueList and goes straight to
HistorianClient.AddNonStreamedValueAsync) ALSO fails with 129
TagNotFoundInCache against SysTimeSec, even with validate=false.
So the cache check is inside the native C++ HistorianClient's
per-connection tag list — there's no managed-callable bypass.
Critical insight discovered: the SDK doesn't use the C++ HistorianClient
at all. It talks WCF directly. The cache gate that blocks the native
wrapper may not block a managed WCF client because the gate is enforced
by aahClientManaged, not by the WCF server.
This shifts the recommendation for any future D2 attempt from "wrap the
native API" (which is genuinely blocked) to "implement the wire path
directly on top of the existing ITransactionServiceContract methods and
test against the live server" (unverified but plausibly viable). The
harness can't help with that path — the wrapper itself is the blocker
we'd be bypassing.
177/177 tests still pass; harness gains --write-revision-direct flag
for further probing of the native-wrapper path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Extended the harness with --write-revision-target-tag <name> (overrides
the value's TagKey via SQL lookup) and --write-revision-skip-validate
(passes false to AddNonStreamedValue's `validate` boolean). Added
--write-revision-commit gate so the harness validates without actually
calling SendValues by default — important when targeting system tags.
Probed SysTimeSec (wwTagKey=12, server-cache-resident system tag):
- AddNonStreamedValue: ErrorCode=TagNotFoundInCache (129) — same failure
- With validate=false: same failure (the cache check is intrinsic, not
gated by the boolean)
Conclusion: the gate is per-(client-session, tag), not per-server-cache.
Even tags the SERVER cache knows about are rejected because the LIBRARY
maintains a separate per-connection tag list that AddNonStreamedValue
checks. That list isn't populated by knowing the wwTagKey alone — it
needs whatever mechanism (RegisterTags2 / read flow side effect / IO
server registration) that we haven't reverse-engineered.
The revision-write path remains architecturally blocked for managed
clients. Plan doc updated with the SysTimeSec finding.
177/177 tests still pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Drove the revision-write flow via reflection in the native trace harness
(--write-revision-values) to see whether it bypasses the AddS2
architectural blocker. It doesn't.
Findings:
- HistorianAccess.CreateHistorianDataValueList(NonStreamedOriginal) succeeds
- HistorianDataValueList.NonStreamedValuesBegin() succeeds (batchID 0->1)
- HistorianDataValueList.AddNonStreamedValue(value, validate=true, out err)
FAILS with ErrorCode=TagNotFoundInCache (129) — same client-side
validation gate that blocks AddS2
- AddNonStreamedValuesEnd() returns void; SendValues() returns true
with Success because the list is empty (no value was ever added)
- No AddNonStreamValues* WCF calls reach the wire
Conclusion: the revision-write path requires the tag to be in the
library's runtime tag cache, which is only populated by configured
IO server / Application Server pipelines, not by HistorianAccess.AddTag.
This matches the architectural blocker documented for AddS2 and means
no public WriteRevisionsAsync / BeginRevisionAsync should be added to
the SDK — the path is unreachable for client-created sandbox tags.
The Wcf/Contracts/ITransactionServiceContract methods (AddNonStream-
ValuesBegin/AddNonStreamValues/AddNonStreamValuesEnd) remain declared
for completeness; no orchestrator or public surface is added.
The harness extension is preserved as a deterministic reproducer for
the blocker: re-run --write-revision-values to verify the gate any
time. docs/plans/revision-write-path.md updated with the empirical
finding plus the original plan retained as historical context.
177/177 tests still pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Plan: docs/plans/speculative-items-sweep.md (also covers parallelism +
findings).
Implemented:
- C3: HistorianTagDefinition.IntegralDivisor (default 1.0). Wire bytes
flip per the captured native serializer; live probe shows the server
stores IntegralDivisor on EngineeringUnit (shared) rather than per-tag,
so the value is accepted on the wire but doesn't visibly persist for
the test EU. Documented in the property's doc-comment.
- E: HistorianWcfCertOptionTests (5 tests) covering AllowUntrustedServer-
Certificate validator installation + ServerDnsIdentity propagation
through CreateEndpointAddress and CreateBindingPair.
Investigated + documented (deferred):
- D3: Discrete/String/Int1/Int8/UInt8 EnsT2 root cause — server-side
ValidationFailed: "Transaction validation failed". Native AddTag's
validator rejects non-analog types; not a wire-format issue. To unlock,
need to capture a working native flow via a different code path
(likely SMC's tag-import path or AddTagExtendedProperties carrying
type-specific metadata). Defer until a customer asks.
- D1: AddTagExtendedProperties feasibility — managed surface confirmed
(ArchestrA.HistorianAccess.AddTagExtendedProperties + WCF op
AddTagExtendedPropertyGroups). Cost estimated at 1-2 days of focused
RE work due to CTagExtendedPropertyGroup payload complexity. Defer.
- D2: AddRevisionValuesBegin/Value/End — sub-plan written at
docs/plans/revision-write-path.md with 5-step capture sequence,
workstream estimates, and risk register. Implementation deferred.
177/177 tests pass (was 172; +5 cert tests + 1 IntegralDivisor unit
test, harness probe results not committed).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty