The batched ingest's append-failure catch had zero coverage, and two doc
statements overstated the loss: the Warning said the burst's values were
"dropped", and RecorderStatus.OutboxAppendFailures said "the value was
dropped, not recorded". The outbox contract is prefix-never-orphan, so a
partial-prefix failure leaves entries durably queued that drain normally.
- New test pins the branch: one 3-item burst whose group commit commits a
1-entry prefix then throws => OutboxAppendFailures == 1 (per burst, not
per value), TotalRecorded == 0, actor alive, and the prefix still reaches
the writer via the post-failure DrainTick (drainInterval 30s, so the
steady cadence cannot account for it). Falsified twice: counting per item
and dropping the drain nudge each turn it red.
- Second test pins the OperationCanceledException filter from its
observable side - a cancel that is NOT shutdown is metered, not swallowed.
Removing the 'when (_lifetime.IsCancellationRequested)' turns it red. The
shutdown side has no cheap seam (the counter dies with the actor).
- Docs corrected: OutboxAppendFailures counts FAILED BATCH APPENDS, one per
burst whatever its size (a granularity change from the per-value era), and
is not a count of values lost; TotalRecorded under-counts when a commit
fails after a partial prefix. Log message says "failed to append" and
names the prefix. No functional change beyond the message string.
Also folds in the DrainBatchSize default alignment behind 0298a0b9: the
recorder's two ctor defaults and its non-positive fallback still said 64
while ContinuousHistorizationOptions.DrainBatchSize now defaults to 1024.
No test pinned the old 64.
C1 — a non-rebuild apply reporting failedNodes > 0 no longer advances _lastApplied.
Pre-delta-materialisation the full passes re-ensured every node on every apply, which
silently repaired any prior swallowed sink fault. The delta path removed that accidental
self-healing: a failed node sat inside _lastApplied, never appeared in a diff set again,
and EnsureVariable early-returns on the ones that landed — so it was lost until an
unrelated change forced a rebuild. The advance also moved to AFTER the materialise
passes, so a throwing pass leaves _lastApplied at the previous composition too. A
rebuild still advances even with failures (the ratchet is its resync path).
I2 — a UnsReferenceDelta whose identity is unchanged (same NodeId, EquipmentId and
BackingRawPath) is now applied in place via UpdateTagAttributes(Uns) instead of
remove+recreate, so the mirror's MonitoredItems survive an operator historizing or
reshaping the raw tag behind them. Remove+recreate stays for identity-changing deltas
(re-point, effective-name edit).
I3 — RemoveVariableNode severs the inverse half of every outgoing Organizes edge, the
variable-node counterpart of UnwireAlarmNotifiers. Rebuilds used to sweep these up;
surgical applies made rebuilds rare, so they accumulated on the raw node for the life of
the process.
I5 — added UNS reference variables are announced (their equipment folder is the parent,
already the Uns realm). Raw adds still are not; the gap comment now says so honestly
rather than calling it neutral and pre-existing.
I4 + M1 — corrected two comments that no longer described the code: the "re-point →
rebuild" claim in ApplyPureRemove, and the "N lock acquisitions" rationale for the delta
passes (Ensure* early-return on a dictionary probe before the lock).
Adversarial review of 9f68f272 (classifier: non-alarm raw-tag deltas became
surgical) found stale UNS inheritance after a surgical raw edit. Editing a raw
tag's IsHistorized / HistorianTagname / IsArray / ArrayLength left every
referencing UNS node STALE: none of those fields were on UnsReferenceVariable,
so no coincident UnsReferenceDelta fired; the applier updated the raw node in
place; and EnsureVariable early-returns on an existing node. Consequences:
HistoryRead through the UNS NodeId served a different series than through the
raw NodeId (breaking the documented dual-registration invariant), a
de-historized tag kept serving history via UNS, and a scalar->array flip left
the UNS mirror scalar AND writable (bypassing the array read-only write gate).
UnsReferenceVariable now carries Backing{IsHistorized,HistorianTagname,IsArray,
ArrayLength}, copied from the backing tag's TagConfigIntent at compose time, so
record equality makes the reference Changed in the SAME plan. Both deltas are
non-rebuild kinds, so the existing machinery repairs the mirror surgically:
remove-previous in Apply, recreate in MaterialiseUnsReferences. That pass now
reads the four values from the RECORD (the single truth the planner diffed)
instead of a rawByPath back-lookup, preserving historian resolution exactly
(blank override => BackingRawPath, which is the backing tag's NodeId).
The artifact-decode seam needs no change: DeploymentArtifact.BuildRawAndUnsSubtrees
drives AddressSpaceComposer.Compose verbatim, which is what guarantees byte-parity.
The classifier needs no change either (a UnsReferenceDelta never forces Rebuild);
its comment now records why.
Also from the same review: a three-place-contract comment on RawTagPlan's
hand-written Equals naming its two downstream consumers, plus classifier pins for
the .Any(!eligible) quantifier, an ArrayLength-only delta, and an
alarm-content-only delta.
ConfigComposer gzips the serialised snapshot (CompressionLevel.Fastest)
immediately after SerializeToUtf8Bytes and BEFORE taking the SHA-256, so
the compressed bytes ARE the artifact everywhere: Deployment.ArtifactBlob,
the LocalDb cache chunks, the gRPC fetch stream, and the RevisionHash a
FetchAndCache node verifies against. The invariant the deploy path rests on
— RevisionHash == SHA-256(stored/wire bytes) — is preserved, which is what
leaves the fetcher, the cache and the serve path untouched: nothing between
the composer and DeploymentArtifact.Open ever looks inside the blob.
Read side: Open() sniffs the gzip magic 1F 8B (valid JSON can never start
with 0x1F, so no framing of our own is needed) and inflates through a size
guard — MaxDecompressedBytes, 512 MiB, internal + mutable so the guard can
be exercised without inflating half a gigabyte per test run. Pre-upgrade
uncompressed blobs take the identical path they always did.
Every decompression failure — corrupt stream, truncated stream, over-limit
inflation — is reported as JsonException, the same exception family the
malformed-JSON path already owns. So the lenient static wrappers still
degrade to empty results and the apply paths still fail the apply and keep
last-known-good (#485); no caller's decision changes because the reason the
bytes are unusable changed.
gzip output is not guaranteed byte-stable across .NET releases. Harmless
here: the hash is computed FROM the emitted bytes at compose time and never
re-derived from the JSON, so the worst an implementation change costs is
one spurious "changed" revision after a runtime upgrade. Snapshot
determinism is unaffected — compression wraps the final bytes and reorders
nothing.
Tests: gzip/uncompressed parity through both the instance parses and the
statics, corrupt-gzip leniency through the wrappers, the size guard (with a
falsifiability control proving the same bytes inflate fine under the
production limit), and composer-side blob-starts-with-1F8B +
RevisionHash == SHA256(blob) with a control proving the hash is NOT over
the JSON.
Task 4 (9f68f272) taught AddressSpaceChangeClassifier that a non-alarm
RawTagDelta and any UnsReferenceDelta are surgical-eligible, so such plans
started classifying AttributeOnly/PureAdd instead of Rebuild. The applier's
surgical branch did not know about either delta set, so those deploys fell
through as SILENT NO-OPS (or, on a non-surgical sink, applied nothing at all
where a rebuild was the safe answer). This closes that gap:
- Raw-tag loop: an eligible ChangedRawTags delta is applied IN PLACE via
ISurgicalAddressSpaceSink.UpdateTagAttributes in the RAW realm, computing
writable (`Writable && !IsArray`) and the historian tagname (blank override
⇒ the RawPath) exactly as MaterialiseRawSubtree does. A delta whose ONLY
difference is ReferencingEquipmentPaths is node-inert for a value tag and
is SKIPPED entirely — that is the shape a single UnsTagReference add/drop
produces, and it used to rebuild the world.
- UNS-reference loop: a ChangedUnsReferenceVariables delta removes the
PREVIOUS node in place (terminal Bad, then RemoveVariableNode, Uns realm).
Remove+recreate rather than an in-place update because a re-point must move
the Organizes edge (the sink has no RemoveReference) and a display-name
edit changes the NodeId itself; the cost is that one node's monitored
items, versus every subscription server-wide today.
- The branch trigger now fires for both sets, so a non-surgical sink falls
back to a full rebuild instead of applying nothing.
Every new operation is inside the existing one-way rebuild ratchet: any false
or throw ⇒ SafeRebuild(). The eligibility filter is defense-in-depth — when
kind != Rebuild the classifier already guarantees every delta is eligible.
The recreate of a changed UNS reference is NOT done here. Until Task 6 the
publish actor still materialises the FULL composition after Apply returns, so
the existing MaterialiseUnsReferences pass recreates it and the system is
correct end to end after this commit; the remove-then-recreate ordering holds
because Apply returns before the materialise passes run. Task 6 narrows those
passes to the plan's delta and keeps the same ordering.
Tests: 7 new applier tests (in-place raw update incl. array/override parity,
reference-only skip, UNS-ref remove, both ratchet fallbacks, non-surgical-sink
rebuild). RecordingSink now captures the realm on surgical / remove / value-write
calls, so the existing UNS-realm assertions are explicit too.
Every public entry point on DeploymentArtifact took ReadOnlySpan<byte> and did
JsonDocument.Parse(blob.ToArray()) — a full copy plus a full document build per
call — so one apply paid ~8-11 full parses of the same bytes (the scoped
ParseComposition alone parsed three times: scope, composition, BuildClusterSets).
DeploymentArtifact.Open(byte[]) now parses once into ParsedDeploymentArtifact,
which owns the JsonDocument and exposes an instance method mirroring each static
entry point. The moved bodies operate on Root; BuildClusterSets takes JsonElement
instead of re-parsing the blob; ResolveClusterScope is memoized per node id, since
every consumer of one apply asks about the same node.
Every static is now a thin wrapper (Open + delegate + dispose) keeping its
ReadOnlySpan<byte> signature and its lenient empty/malformed contract — the
wrapper pays the one copy and owns the JsonException catch, so output shapes are
unchanged. Hot callers migrate to Open() separately.
ParsedDeploymentArtifactTests pins same-bytes-same-output through both doors for
all six entry points over a rich multi-cluster artifact (raw chain + UNS refs +
scripts + keys + ACLs), with falsifiability controls proving the fixture actually
scopes, plus memoization and after-dispose-use coverage.
Joseph Doherty