CreateEnvelope stamped Sequence with an interlocked increment when the
envelope was built, so two concurrent InvokeAsync callers could take 1
and 2 and then enqueue in the order 2, 1 — non-monotonic on the wire,
breaking gateway.md's "monotonic per sender" contract. Benign today
(neither side validates inbound sequence, old GWC-10 still open) but it
would fault healthy sessions the moment worker-side validation lands.
WriteLoopAsync now stamps immediately before _writer.WriteAsync. It is
the outbound channel's single consumer (SingleReader = true), so wire
order and stamp order are the same thing by construction and
_nextSequence drops to a plain ulong with no interlocking. This mirrors
the worker's WRK-04 fix, which the gateway half never received.
Also adds TST-28: a [Theory] pinning that GatewayHello.MaxFrameBytes
carries the configured worker-frame maximum (default + 2 MiB override).
The adoption half is asserted only in the Windows-only worker suite, so
a regression to sending 0 — "older gateway, use default" to the worker —
would silently downgrade the negotiated IPC-02 limit with every CI test
still green. Mutation-checked (hard-coded 0 fails both cases).
Tests: WorkerClientTests.ConcurrentInvokesEmitStrictlyIncreasingSequences
OnTheWire (32 parallel invokes; failed 3/3 pre-fix) and
.StartAsync_SendsGatewayHelloWithConfiguredMaxFrameBytes.
The GWC-04 remediation decoupled the read loop from event backpressure by
staging events into an unbounded channel, so its TryWrite always succeeded and
the only overflow fault was a single timed WriteAsync exceeding
EventChannelFullModeTimeout. A consumer draining slower than the worker
produces — each individual write still completing inside the window — therefore
grew gateway memory without bound, without a fault, and without a metric: the
queue-depth gauge counted only the bounded consumer channel, so staged events
were invisible.
Bound _eventStaging at 2 x EventChannelCapacity (Wait, single reader/writer, no
synchronous continuations). A rejected staging TryWrite is the sustained
slow-drain signal and faults the client ProtocolViolation with
QueueOverflow("worker-event-staging"), guarded by IsTerminalState() so a
completed channel during shutdown stays a silent drop. SetFaulted is
non-blocking, so the read loop still never awaits behind events. The timed-write
fault is unchanged and still catches the full-stall case earlier.
Move the queue-depth increment from EnqueueWorkerEventAsync to StageWorkerEvent
so the single counter reports total undelivered events (staged + queued); the
decrement at consumer read was already correct. No new configuration key: the
bound is derived, and gateway-side buffering per session is now at most
3 x MxGateway:Events:QueueCapacity. Coordination with still-open GWC-21
(EventChannelFullModeTimeout configurability) remains open and was not blocked
on.
Tests: StagingChannelOverflowFaultsWorkerWithoutWaitingForFullModeTimeout (5-min
full-mode timeout so only the staging bound can fire; asserts an interleaved
command reply still completes) and WorkerEventQueueDepthGaugeCountsStagedEvents.
Docs updated in the same change: GatewayProcessDesign, MxAccessWorkerInstanceDesign,
GatewayConfiguration, Metrics. GWC-24 flipped to Done in both trackers.
Resolve all CommentChecker findings across the gateway server, worker, tests,
and .NET client (314 -> 0 real issues): add missing <returns>/<summary>/<param>
on public and test members, convert Stream/interface overrides to <inheritdoc/>,
and remove internal task/issue tracking IDs (SEC-*, IPC-*, WRK-*, GWC-*, TST-*,
Client.Dotnet-*) from shipped code documentation while preserving the design
rationale prose. Shipped comments should not carry internal bookkeeping, and
complete XML docs keep the analyzer/TreatWarningsAsErrors gate and generated API
docs clean. The 6 remaining flags are heuristic false positives (MD5, UTC-4,
capacity-1, near-1601) left intact so real documentation is not corrupted.
Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW
Behavior-preserving allocation cuts on the per-event/per-command path:
- GWC-06: StreamEvents send-timing uses Stopwatch.GetTimestamp() +
GetElapsedTime() instead of a per-event Stopwatch allocation (same measured
span).
- GWC-07/IPC-05 (event): MapEvent transfers ownership of the inner MxEvent
instead of .Clone()-ing it. Safe: WorkerEvent is parsed fresh per pipe frame
with the distributor pump as its single consumer (GWC-01), MapEvent runs once
before fan-out, and every downstream consumer (subscribers, replay ring)
only READS the event (WorkerSequence is stamped upstream; verified no
post-mapping mutation). Comment documents the invariant + restore-clone
caveat if a second consumer is added.
- IPC-05 (command): CreateCommandEnvelope no longer re-clones; MapCommand
already isolated the graph from the caller-owned gRPC message.
- GWC-15: grpc_stream_queue.depth converts from a per-event push counter to an
ObservableGauge summing registered channel sources at scrape time only
(name/semantics unchanged); removes all per-event .Count/lock work.
Kept every load-bearing isolation clone (MapCommand, Invoke, bulk filters,
MapCommandReply). Server build clean (0 warnings); EventStream/Metrics/
Distributor/Mapper tests 62/62 (incl. formerly-flaky queue-depth tests, now
green under the lazy gauge, + 2 new MapEvent ownership tests). Docs: Metrics.md,
Grpc.md.
Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW
Gateway server-side named-pipe frame path, wire format byte-identical:
- Writer (GWC-08/IPC-13): serialize once into a single ArrayPool-rented buffer
holding the 4-byte LE length prefix + payload, then one WriteAsync. Removes
the second serialization pass (ToByteArray re-ran CalculateSize), the
separate prefix array + second stream write, and per-frame heap allocation.
- Reader (IPC-14): rent the payload buffer from ArrayPool instead of new byte[]
per frame; read/parse bounded to the real length, return in finally. Matches
the worker side which already pools.
- Correctness: length tracked separately from (larger) pool capacity; every
rented buffer returned exactly once in finally incl. the malformed-protobuf
path; ParseFrom copies into the message so the envelope never aliases the
returned buffer.
Cross-checked LE-prefix framing agrees across gateway+worker writer/reader.
Server build clean (0 warnings); WorkerFrameProtocol tests 10/10 incl. a new
large-payload-near-cap round-trip (forces pool buffer > frame). The 2 failing
WorkerClient/FakeWorkerHarness tests are the known macOS UDS 104-char path
limit, not a regression.
Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW
The read loop awaited EnqueueWorkerEventAsync inline, which blocks in the bounded
event channel's timed WriteAsync (up to EventChannelFullModeTimeout, default 5s)
when the channel is full with no/slow consumer. A WorkerCommandReply or heartbeat
queued behind an event frame was then stalled, so an in-flight InvokeAsync could
hit CommandTimeout even though the worker replied in time.
Mirror the existing outbound WriteLoopAsync: add an unbounded event staging
channel and a dedicated EventWriteLoopAsync. DispatchEnvelope is now fully
synchronous — the WorkerEvent branch hands the event off with a non-blocking
TryWrite and the read loop never awaits. The event write loop owns the timed
WriteAsync into the bounded channel and the sustained-overflow ProtocolViolation
fault (unchanged contract). Registered in WaitForBackgroundTasks + completed on
close/fault/dispose.
Test: reply arriving after events with a full, consumer-less event channel is
dispatched promptly (no CommandTimeout) — pipe-harness, verified on windev.
Docs: GatewayProcessDesign read/write/event-loop section.
Proto foundation + gateway-side of the size/backpressure pass:
- IPC-02: add GatewayHello.max_frame_bytes (regen Generated/); gateway sends
its negotiated worker-frame max in the handshake so the worker can adopt it
instead of a hard-coded default. Worker read-half lands separately.
- IPC-03: give the pipe frame max envelope-overhead headroom above the public
gRPC cap (WorkerFrameProtocolOptions.EnvelopeOverheadReserveBytes = 64 KiB;
default Worker.MaxMessageBytes bumped to 16 MiB + reserve), cross-validate the
headroom at startup, and pre-check command envelope size in WorkerClient so an
oversized command fails only that correlation (ResourceExhausted) instead of
faulting the whole session.
- IPC-04: reject DrainEvents max_events above a public ceiling in the request
validator (worker per-reply cap lands with the worker half).
Docs: GatewayConfiguration, WorkerFrameProtocol, gateway.md.
Tests: headroom validation, DrainEvents bound, oversized-command per-command
failure (pipe-harness, verified on windev).
Interlocking changes across the gateway server (shared GatewaySession.cs /
SessionManager.cs), committed together:
- GWC-01 (Critical): alarm monitor now attaches as an internal
(non-counted) distributor subscriber instead of a second raw drain of the
single worker event channel; WorkerClient._events -> SingleReader with a
claimed-once guard so a future dual-consumer regression throws loudly.
- GWC-02 (High): faulted sessions are swept in CloseExpiredLeasesAsync
(IsFaultedReapable + FaultedReason); new FaultedGraceSeconds (default 0).
- GWC-03 (High): configurable MaxSparseArrayLength (default 1_000_000)
enforced before allocation.
- TST-02 (High, security): StreamEvents attach now enforces the opening key
id -> PermissionDenied on owner mismatch.
- TST-12 (Medium): CLAUDE.md retention-defaults sentence corrected.
Verified: NonWindows build clean; targeted tests 135/135 on macOS, plus
WorkerClientTests 18/18 on the Windows host.
Apply the ZB.MOM.WW. prefix to all gateway-side projects, folders,
.csproj/.sln contents, C# namespaces, using directives, generated proto
C# (csharp_namespace + checked-in generated files), InternalsVisibleTo
attributes, project-name string literals (LoadProject, .sln lookups,
worker exe paths, staticwebassets manifest), and the install/script/doc
references that point at any of the above. Migrate the solution from
.sln to .slnx via `dotnet sln migrate` and delete the old file.
External-runtime identifiers are intentionally NOT prefixed so external
configuration keeps working:
- GatewayMetrics.cs MeterName ("MxGateway.Server")
- DashboardAuthenticationDefaults Scheme/Policy ("MxGateway.Dashboard")
- GatewayRequestLoggingMiddleware logger category ("MxGateway.Request")
- StaRuntime thread name ("MxGateway.Worker.STA")
- appsettings.json root section "MxGateway" + env-var prefix
MxGateway__... and secret-name MxGateway:ApiKeyPepper
- C:\ProgramData\MxGateway\ data dir paths
Also fixes two tests that were not rename-related but became visible
while validating the rename:
- WorkerLiveMxAccessSmokeTests.ShutDownAsync: cancellation that the
gateway service correctly maps to RpcException(Cancelled) per gRPC
convention was being misclassified as a stream fault. Added a sibling
catch on RpcException with StatusCode.Cancelled.
- IntegrationTestEnvironment.ResolveRepositoryRoot: extracted IsRepositoryRoot
and made it accept either a .git marker OR a .sln/.slnx next to src/
so the worker-exe walker works in non-git working copies.
clients/proto/proto-inputs.json's protoRoot updated to point at
src/ZB.MOM.WW.MxGateway.Contracts/Protos.
Verified by `dotnet build` and a full `dotnet test` of the .slnx with
MXGATEWAY_RUN_LIVE_{MXACCESS,LDAP,GALAXY}_TESTS=1:
Tests: 472/472 pass
Worker.Tests: 280/280 pass (4 dev-rig [Fact(Skip=...)] skipped)
IntegrationTests: 18/18 pass
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty