The D2 storage-engine-pipe wall is WCF-transport-specific. On the 2023 R2 gRPC
front door, TransactionService is a first-class service AND the gateway to the
storage engine, so the Open2 storage-session GUID (uppercase) is accepted
directly as strHandle with no legacy pipe.
Live-verified against the real 2023 R2 server over a write-enabled (0x401) gRPC
session: AddNonStreamValuesBegin returns a real strTransactionId, and
AddNonStreamValuesEnd(bCommit=false) discards it cleanly (no data written). On
2020 WCF the same op returns UnknownClient(51) for every handle + priming chain.
- HistorianGrpcRevisionProbe + grpc-revision-probe CLI command + gated test
NonStreamedWriteTransaction_OverGrpc_BeginsAndDiscards (live pass).
- HistorianGrpcHandshake.OpenSession gains an optional connectionMode param
(default read-only 0x402; pass 0x401 for write-enabled) — non-breaking.
- Docs: revision-write-path.md "the wall is gone" section; roadmap M3 section,
R3.1-R3.3 rows, one-glance table, and status note updated honestly.
Not yet shipped: the AddNonStreamValues btInput VTQ buffer is uncaptured (never
guess wire bytes), so no value-commit is implemented. Scope is non-streamed
ORIGINAL backfill; revision EDITS (R4.2) remain pipe-only even on gRPC.
272 unit tests pass; sanitization scan clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Live-probed both R1.3 and R1.4 against a real 2023 R2 server over the gRPC
StatusService; implemented the one that carries an evidence-backed value.
R1.3 GetServerTimeZoneAsync — SHIPPED:
- StatusService.GetSystemTimeZoneName(uiHandle) returns the real server zone
over RemoteGrpc (the 2020 WCF op is a client-side stub returning empty).
- HistorianGrpcStatusClient.GetSystemTimeZoneNameAsync -> dialect routing ->
public HistorianClient.GetServerTimeZoneAsync. Non-gRPC transports fail
closed with ProtocolEvidenceMissingException (no empty-string lie).
- Golden message-shape unit test + non-gRPC guardrail unit test + gated live
test. 271 unit tests pass.
R1.4 GetHistorianInfoAsync (EventStorageMode) — bounded out on gRPC too:
- gRPC GetHistorianInfo is the same named-value query as 2020 WCF (only
HistorianVersion resolves); EventStorageMode + 7 variants fail on both
GetHistorianInfo and GetSystemParameter. The 518-byte struct is filled by a
native vtable+648 HCAL call, not the gRPC op (per the 2023 R2 decompile), so
the field is never on the wire. Not shipped on any transport. Closes the
roadmap's open "build against a live 2023 R2 server" caveat.
Also correct the stale M3 roadmap section: D2 already proved
Transaction.AddNonStreamValues* rides the storage-engine pipe (STransactPipeClient2
-> aaStorageEngine), not WCF — same wall as R4.2 — so M3-over-WCF is blocked, not
"the path that is NOT the gated cache push".
Docs: hcal-roadmap.md, wcf-historian-info.md, wcf-status-localhost.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Probes the 2023 R2 gRPC browse path and records the finding. The front door does
NOT hit the 2020 WCF metadata-server-pipe wall.
- RetrievalService.StartTagQuery is cracked: the server (CMdServer::StartActiveTagnamesQuery
over \.\pipe\aahMetadataServer\console) parses the filter as OData. startswith()/
contains()/eq/empty succeed and return the 8-byte (queryHandle, tagCount); SQL-LIKE "%"
and glob "*" fail with "ODataFilter: bad token". Live: 220 Sys* tags counted.
- QueryTag (paging) remains: every guessed btRequest returns a constant native error
type 4 / code 72 (content-independent) -> framing needs a native capture, not guessing.
Adds RE probe helpers Grpc/HistorianGrpcTagClient.ProbeStartTagQuery + ProbeTagQuerySequence,
a gated StartTagQuery_OverGrpc_AcceptsODataFilter test, and the finding doc
docs/reverse-engineering/grpc-tag-query-odata.md. Browse is not yet wired (QueryTag open).
217 unit tests pass; 5/5 live gRPC tests pass. No tag names/identities committed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Routes HistorianClient.GetTagMetadataAsync over gRPC when Transport==RemoteGrpc,
via the new Grpc/HistorianGrpcTagClient calling RetrievalService.GetTagInfosFromName
(the plural string-handle metadata op).
- String handle = the Open2 storage-session GUID formatted uppercase (the format
that resolves the native string-handle path); threaded out of the shared handshake
via a new HistorianGrpcHandshake.Session { ClientHandle, StorageSessionId, StringHandle }.
- Request btTagNames = uint count + per-name(uint charCount + UTF-16LE) — golden-byte
unit-tested (BuildTagNamesBuffer).
- Response btTagInfos = uint count + CTagMetadata records — decoded by the existing
HistorianTagQueryProtocol.ParseGetTagInfoResponse; data type via the shared MapDataType.
The 2020 WCF string-handle wall does NOT apply on the gRPC front door, as the
string-handle-wall RE note predicted. LIVE-VERIFIED against a real 2023 R2 server:
GetTagMetadataAsync returns the requested tag with a valid decoded data type.
216 unit tests pass. Captured framing confirmed live then discarded; no tag names
or identities committed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Roadmap docs/plans/hcal-roadmap.md, milestone M0 (gRPC parity for the DONE
surface). Now unblocked for live verification by a reachable 2023 R2 server.
- R0.4 Probe over gRPC: new HistorianGrpcProbe calls History/Retrieval/Status
GetInterfaceVersion (unauthenticated). ProbeAsync routes over gRPC when
Transport==RemoteGrpc. LIVE-VERIFIED against a real 2023 R2 server — needs no
credentials (runs before the auth loop), so it works despite the auth blocker.
- R0.3 System parameter over gRPC: new HistorianGrpcStatusClient calls
StatusService.GetSystemParameter over the authenticated session; routed in the
dialect. Built + unit-tested (request/response field mapping pinned).
Live-verification pending an auth fix (see below).
- Extracted the proven auth handshake from HistorianGrpcReadOrchestrator into
shared Grpc/HistorianGrpcHandshake (reused by read + status + future
browse/metadata). Repointed the IL structural guardrail test to it.
- Diagnostics: round-failure now decodes the native server error + hex/ASCII
preview (HistorianNativeHandshake.DescribeError). This surfaced the live auth
blocker as SEC_E_LOGON_DENIED (0x8009030C) at NTLM round 1 — framing is correct,
the credential did not validate. Probable cause: stale file password or NAM-domain
NTLM restriction (Kerberos/RDP works, NTLM denied; no SPN path over the tunnel).
216 unit tests pass; live gRPC probe passes. Sanitization scan clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Stands up HistorianTransport.RemoteGrpc end-to-end for the read path,
built on the recovered 2023 R2 gRPC contract (gRPC-Web/HTTP-1.1, port
32565, gzip). The opaque protobuf `bytes` fields carry the SAME native
binary payloads as the 2020 WCF/MDAS path, so the proven serializers and
parsers are reused unchanged.
- Grpc/Protos/*.proto: 6 protoc-validated contracts recovered from
embedded FileDescriptors (authoritative, not guessed).
- Grpc/HistorianGrpcChannelFactory: GrpcWebHandler/HTTP-1.1 channel,
ResolvePort/ResolveAddress, optional TLS + gzip.
- Grpc/HistorianGrpcReadOrchestrator: mirrors the WCF read chain over
gRPC; auth uses HistoryService.ExchangeKey (the gRPC ValCl op).
- Wcf/HistorianNativeHandshake: transport-agnostic Open2 request builder
+ SSPI/Negotiate token loop + response decode, shared by WCF and gRPC.
- Op map (2020 -> gRPC): ValCl->ExchangeKey, Open2->OpenConnection,
StartQuery2->StartQuery, GetNextQueryResultBuffer2->GetNextQueryResultBuffer.
- HistorianClientOptions: DefaultGrpcPort=32565, GrpcUseTls.
- csproj: Google.Protobuf, Grpc.Net.Client(.Web), Grpc.Tools codegen.
Not yet live-verified against a 2023 R2 server: ExchangeKey is the first
thing to revisit if a live server rejects the handshake; the inner byte
payloads are the proven 2020 protocol. Gated live test via
HISTORIAN_GRPC_HOST. 188 unit tests green; build clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Joseph Doherty