Files
histsdk/docs/reverse-engineering/wcf-status-localhost.md
T
Joseph Doherty 4da5287d01 R1.2 GetRuntimeParameter + string-handle wall RESOLVED (handle-format bug)
Execute HCAL roadmap R1.2 (GetRuntimeParameterAsync) end-to-end, and in doing so
discover that the "string-handle wall" blocking R1.1/R1.4/R1.5/R1.6 was a handle
FORMAT bug, not a missing native session/filter registration.

R1.2 (shipped, live-verified):
- Captured native GetRuntimeParameter -> WCF op aa/Stat/GETRP (string-handle op,
  GETHI's shape), via scripts/Capture-RuntimeParam.ps1 + instrument-wcf-{write,read}message.
- HistorianRuntimeParameterProtocol serializes pRequestBuff (54 67 01 00 + uint
  nameCount + per-name uint charCount + UTF-16) and parses pResponseBuff (version +
  uint resultCount + CRetVariant 0x43 VT_BSTR + uint16 len + uint16 charCount + UTF-16).
- IStatusServiceContract2.GetRuntimeParameter (GETRP) op; HistorianWcfStatusClient
  passes the Open2 storage-session GUID as the string handle, UPPERCASE.
- Public HistorianClient.GetRuntimeParameterAsync(name) via the dialect.
- Golden WcfRuntimeParameterProtocolTests + gated live test; returns HistorianVersion.

String-handle wall RESOLVED (proven, public APIs deferred):
- The Open2 storage GUID works as the string handle when sent UPPERCASE
  (ToString("D").ToUpperInvariant()); earlier "blocked" probes used lowercase.
- Live-probed GETHI (R1.4) -> returns data; ExeC (R1.1) -> Retr.GetV prime -> ExeC ->
  GetR returns a BinaryFormatter-serialized .NET DataTable. Gated
  StringHandleProbeDiagnosticTests + scripts/Capture-ExecSql.ps1 + exec-sql harness scenario.
- Docs flipped: wcf-string-handle-wall.md RESOLVED banner; roadmap R1.1/R1.4 reachable,
  R1.5/R1.6 likely; wcf-status-localhost.md GETRP section.
- R1.1/R1.4 public APIs NOT shipped: ExeC needs a GetR paging loop + a BinaryFormatter-
  stream parser (BinaryFormatter is removed from .NET 10); GETHI full-info struct needs
  its own capture.

223 unit tests pass; gated live tests green against the local 2020 Historian.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
2026-06-20 22:10:31 -04:00

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3.8 KiB
Markdown

# WCF Status Evidence
Commands:
```powershell
dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-status localhost 32568
dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-status localhost 32568 Version
```
Confirmed:
- The local status endpoint is `net.tcp://localhost:32568/Stat`.
- `IStatusServiceContract2` is a static WCF contract named `Stat` in namespace
`aa`. The managed definitions now include `GetSystemParameter`, `GETHI`,
`PNGS`, and `PNGP`.
- `GetInterfaceVersion` returns code `0`, version `0` on the local 2020
install.
- The decompiled `CStatusConnectionWCF.GetServerTime` implementation is a
WCF-path stub that returns success without calling the `Stat` service. The
managed direct call likewise returns code `0` with size `0` and no buffer.
Observed sanitized localhost results:
- `GetSystemTimeZoneName(handle: 0)` returns code `4` and no value.
- `IsDBCaseSensitive(handle: 0)` returns code `4`.
- `GetSystemParameter(handle: 0, "Version")` returns `false` with no error
buffer.
Re-tested 2026-06-20 with a **real authenticated client handle** (full Open2 auth
chain), not `handle: 0`:
- `GetSystemParameter(handle, "HistorianVersion")` → real version string (works;
shipped as `GetSystemParameterAsync`).
- `GetSystemTimeZoneName(handle)` → return code `0x00000000` (success) but an
**empty value string**. Same channel/handle that makes `GetSystemParameter`
return real data, so this is the op's own behavior, not an auth/marshalling
gap. `GetSystemTimeZoneName` is a member of the `GetServerTime` stub family:
the 2020 WCF path returns success without producing a value (the native client
computes the zone locally). It only becomes a real round-trip on the 2023 R2
gRPC front door (`Status.GetSystemTimeZoneName`), which is absent on this box.
Interpretation:
- `Stat` endpoint routing is confirmed, but status operations that require a
real client handle are not usable until managed session open is solved.
- `GetServerTime` should not be promoted into the public SDK as a real server
time call from this WCF path; native evidence shows it is a no-op stub here.
- **`GetServerTimeZoneAsync` (roadmap R1.3) is NOT a trivial WCF op on 2020** — it
is a stub returning empty. Do not ship it over the 2020 WCF transport. Deliver
it only against a live 2023 R2 gRPC server. Reclassified in `docs/plans/hcal-roadmap.md`.
## GETRP / GetRuntimeParameter (roadmap R1.2) — DONE, live-verified 2026-06-20
Captured the native `HistorianAccess.GetRuntimeParameter(List<string>, out List<object>)`
WCF traffic with `scripts/Capture-RuntimeParam.ps1` (instrument-wcf-{write,read}message).
Findings:
- The WCF op is **`aa/Stat/GETRP`** — `bool GETRP(string handle, byte[] pRequestBuff,
out byte[] pResponseBuff, out byte[] errorBuffer)`, i.e. the **same string-handle +
request/response-buffer shape as GETHI**, *not* the simple `GetSystemParameter(uint, string)`
shape the roadmap originally assumed.
- The `string handle` is the **Open2 storage-session GUID** (the value
`ParseOpenConnectionResponse` reads from `outBuff[5..21]`), sent **UPPERCASE, dash-separated,
no braces** (`ToString("D").ToUpperInvariant()`).
- Unlike GETHI (which the earlier probe found blocked), **GETRP succeeds from the pure-managed
client** with that handle: `GetRuntimeParameter("HistorianVersion")` → `20,0,000,000`.
- `pRequestBuff` = `54 67 01 00` (sig+version) + uint nameCount + per name(uint charCount +
UTF-16LE). `pResponseBuff` = version(1) + uint resultCount + CRetVariant(`0x43` VT_BSTR +
uint16 payloadLen + uint16 charCount + UTF-16LE).
Shipped as `HistorianClient.GetRuntimeParameterAsync(name)`. See
`HistorianRuntimeParameterProtocol`, golden `WcfRuntimeParameterProtocolTests`, and the
handle-format lead in `wcf-string-handle-wall.md` §Update (retry GETHI/ExeC uppercased).