Live-probed StorageService.OpenStorageConnection against the 2023 R2 server over a
write-enabled (0x401) session. Every attempt — sweeping ConnectionMode (0x401/0x402/0x1),
StorageSessionId-in (Open2-GUID / empty), and FreeDiskSpace — returns the IDENTICAL native
error type=4 code=85 ("session not registered"), so it's a structural refusal, not a bad
field value.
Decode (two corroborating facts):
- Error 85 is the same code the event read returns before RegisterTags2 (see
HistorianWcfEventOrchestrator) — a generic "session not registered for this op".
- The 2023 R2 decompile shows OpenStorageConnection lives on a SEPARATE GrpcStorageClient
(the storage engine's SF/snapshot channel, own port + service identity); HistorianAccess
drives non-streamed writes through the native C++ HistorianClient, never this op.
So the roadmap's mapped "missing console session" step was wrong. The real non-streamed-write
precondition is the front-door HistoryService.RegisterTags (RTag2-family) for the target tag —
which is exactly why the R3.1 batch failed at AddNonStreamValues (no tag registered ->
StoreNonStreamValues had no route). Matches the original 2020-WCF D2 hypothesis.
Remaining (both need a native gRPC capture; do not guess bytes): the regular-tag RegisterTags
btTagInfos (only CM_EVENT's tag-GUID form is known) and the AddNonStreamValues btInput.
- HistorianGrpcStorageConnectionProbe + grpc-open-storage-connection CLI (opens nothing
persistent; CloseStorageConnection on success)
- corrected revision-write-path.md §R3.1 follow-up + hcal-roadmap R3.1/R3.2 rows
- gated regression test pinning the error-85 refusal
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Joseph Doherty
57b9506d01