Array nodes were forced read-only for every driver. A new single authority,
Core.Abstractions DriverArrayWriteSupport, says which (driver, element type)
pairs encode a whole-array write: Modbus (Coils / numeric HoldingRegisters),
S7 (Byte/Int16/UInt16/Int32/UInt32/Float32), OpcUaClient (pass-through) and
Galaxy (Boolean/Int32/Int64/Float/Double/String/DateTime). Everything else
stays read-only, so the server never advertises a write the driver refuses.
- Composer derives RawTagPlan.ArrayWritable + UnsReferenceVariable
.BackingArrayWritable at compose time (both seams, byte-parity); the
applier's one writability rule is Writable && (!IsArray || ArrayWritable)
for materialise and surgical paths, raw and UNS alike.
- ArrayWritable is on the classifier's surgical raw-tag whitelist and
mirrored on the UNS record (UnsReferenceBackingParityTests updated).
- Node manager refuses a wrong-length / non-array value on an array node
(BadTypeMismatch) and any IndexRange write (BadWriteNotSupported) inline,
before dispatch; WriteOperate/ACL gates and the revert are unchanged.
- Per-driver parity tests pin the table against the real Modbus write path,
S7 EncodeArrayBlock and Galaxy MxValueEncoder (UInt32/UInt64 excluded:
array covariance reinterprets their bits).
- Over-the-wire proof in OpcUaServer.IntegrationTests (ArrayWriteWireTests).
- ValueRank > 1 documented as out of scope by decision (docs/Uns.md).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- AnnounceAddedNodes raises NodeAdded in the Raw realm for the existing parents of
added raw containers/tags (ComputeRawAddAnnouncements); Uns side unchanged.
- ApplyPureRemove removes UNS reference variables BEFORE the equipment subtree, so a
reference the subtree's id-prefix scope reaches no longer ratchets to a full rebuild
(03/P5). A NotSubsumed filter was not used: in production a reference NodeId is
Area/Line/Equipment/Name, outside the subtree scope, so filtering would leak it.
The matching RemoveEquipmentSubtree severing (03/S20) is in the node-manager commit.
- UnsReferenceBackingParityTests: reflection guard discovering the classifier's surgical
raw-tag whitelist and requiring a same-typed mirror field (03/U11).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
CLAUDE.md — a new "How a deploy reaches that address space" block under the v3
Batch 4 address-space section. The blanket ChangedRawTags/ChangedUnsReferenceVariables
=> Rebuild rule is gone, so the doc now names both halves explicitly: what still
rebuilds (alarm-bearing raw-tag deltas, raw-tag identity changes, raw container
renames/removals, changed equipment/alarms) and what is now surgical (non-alarm
attribute deltas, every UnsReferenceDelta). Also records the three semantics that
are easy to break by accident: mirror repair rides UnsReferenceVariable's inherited
backing fields (omitting a newly-inherited field silently reopens the staleness),
a degraded non-rebuild apply deliberately does not advance _lastApplied, and the
raw-realm announce gap is no longer neutral now that surgical adds keep
subscriptions alive.
CLAUDE.md ConfigSource — the RevisionHash == SHA-256(artifact bytes) paragraph is
still true and stays; it gains the clause that the blob is gzip-compressed since
2026-08-15 and the hash covers the COMPRESSED bytes, which is precisely why the
fetcher, cache and serve path were untouched.
docs/Uns.md + docs/Raw.md — one section each on what a deploy now tears down, from
the authoring surface's point of view, including the mirror repair semantics
(identity-preserving backing edits update in place and keep their MonitoredItems;
re-points and effective-name edits remove+recreate that one node).
docs/Configuration.md — "Artifact compression (2026-08-15)" under ConfigSource/
ConfigServe: gzip inside the hashed bytes, magic-sniffed on read, pre-upgrade
uncompressed rows still parse, plus the two operational facts an operator needs.
The first deploy after upgrade re-hashes every revision (same config, new bytes,
new RevisionHash) so it is a one-time full re-dispatch rather than a no-op; and
rollout is ordered — nodes must run artifact-sniffing code BEFORE central starts
emitting compressed blobs, since a pre-upgrade node handed a gzip artifact fails
the apply and keeps last-known-good until it is upgraded.
Plan doc — a "Follow-ups (recorded, not implemented)" section covering the seven
items surfaced during implementation and review: the raw-realm announce gap, the
RemoveEquipmentSubtree dangling-inverse-edge exposure, the missing end-to-end test
for a degraded remove-bearing apply's ratcheted rebuild, the scripted-alarm
thin-plan-ids-against-rich-rows blindness, the absent monotonic dispatch sequence,
LocalDb store ordering under concurrent StoreAsync, and threading the in-hand blob
through RestoreApplied.
tasks.json — all nine tasks completed.
Docs only; no source changes.
Re-ran #489's own repro recipe on docker-dev. It does not reproduce: renaming
pymodbus/plc/HR200X -> HR200Z and deploying (no node restart, container at 0
restarts) yields the new raw NodeId serving live ~1 Hz data, the old NodeId gone
with BadNodeIdUnknown, and the UNS projection still Good.
The mechanism is NOT the ApplyDelta/ReinitializeAsync chain the issue's
2026-07-26 code-trace predicted. The node log shows a stop-and-respawn:
DriverHost: stopped driver child MAIN-modbus
DriverHost: spawned Modbus driver MAIN-modbus (stub=False)
DriverInstance MAIN-modbus: subscribed to 2 refs (poll-sub-1)
#516 moved a DriverConfig change out of toDelta and into toStop+toSpawn so the
factory is the single parse authority. A rename changes the merged DriverConfig,
so the child is rebuilt against the new RawPaths and re-subscribes on the same
deploy. #489 was fixed as a side effect and needs no code change.
Also gated the sibling case the issue did not cover: renaming the *device*
(the middle RawPath segment, plc -> plcz) rebinds identically.
Records the operator-facing fact in docs/Raw.md, including the flip side #516
accepts — a rename reconnects the driver, briefly dropping every tag on it.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
Closes the §7.2 priority-3 item. Sql was a shipped, merged driver with NO
user-facing documentation at all -- only design and plan files, which describe
what was intended rather than what an operator needs to author one.
Sql.md covers: SQL Server as the only constructed provider (the other four
SqlProvider names are reserved, and authoring one fails rather than falling
back), the KeyValue / WideRow tag models with worked TagConfig, Query being
rejected end-to-end, the config table with real defaults read from
SqlDriverOptions, connectionStringRef never carrying credentials into an
artifact, per-source query grouping and its case-sensitive group keys, and the
value-bound-vs-identifier-validated split that makes it injection-safe.
Calculation.md covers: what a pseudo-driver is and why it occupies a driver slot,
a Calculation-vs-VirtualTags decision table (the two are easy to confuse), the
literal-only ctx.GetTag dependency extraction and the runtime-built-path trap,
the two deploy gates, the all-deps-arrived publish gate, and the Good->Bad-once
error semantics.
Two stale claims found by checking against source rather than inheriting them:
- The driver README's Calculation row still carried G-1 ("no typed config form,
RunTimeout unauthorable"), fixed on 2026-07-27 by CalculationDriverForm.
- docs/Raw.md's "one auto-created default Engine device" NEVER SHIPPED. I had
copied it into the new doc before checking; "Engine" has zero occurrences in
src/ and nothing special-cases Calculation at device creation. Corrected in
both files. The config key was also wrong in my first draft: runTimeoutMs, an
int in milliseconds, not a TimeSpan string -- and it is ignored on reinit
because the evaluator's timeout is constructor-fixed.
Full solution: 49 suites pass; the 2 failures are the known pre-existing
environment ones (AbLegacy.IntegrationTests docker fixture, Host.IntegrationTests).
OpcUaClient.IntegrationTests, which was silently failing, is now green.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
Joseph Doherty