Measured the unbounded purge burst and found it can force a full ten-table
snapshot resync, then bounded it. No purge-exemption path was added — the
deletes are still CDC-captured like any other write, which stays ruled out
by design; what changed is how many a single tick performs.
MEASURED (harness: real EventLogPurgeService over a real LocalDb file with
site_events genuinely RegisterReplicated, plus a two-node loopback gRPC
replication pair; docker rig untouched):
393 bytes/row incl. indexes => a 1 GB event log holds ~2,731,947 rows.
Expiring all of them in ONE tick: 285 s, 2,731,947 oplog rows,
284 MB oplog payload, 2.73 M row-version tombstones (7-day retention),
i.e. 2.7x LocalDb's MaxOplogRows default of 1,000,000. Crossing that makes
the 60 s maintenance tick prune the oplog and set needs_snapshot — a FULL
snapshot of all ten replicated tables, bought by a routine retention purge.
The resident backlog is produced-minus-drained, so a healthy peer blunts it:
on loopback the same burst peaked at 391,424 and cleared in 6.0 min. That is
the problem, not the reassurance — the old safety margin was a function of
peer throughput and vanished with the peer down. A bounded tick is safe at
any peer speed.
Drain is not a bottleneck: 7.6k-19.8k tombstones/s (20k / 500k / 2.73M runs).
SHIPPED:
- SiteEventLogOptions.MaxPurgedRowsPerTick (default 250,000; 0 = unlimited
escape hatch, negatives rejected). One SHARED budget across the retention
purge and the cap trim — two independently-capped phases would let a tick
emit twice the intended burst. 4x margin under MaxOplogRows, which is also
shared with every other replicated table's ordinary traffic.
- SiteEventLogOptions.PurgeCatchUpInterval (default 5 min, validated > 0 and
<= PurgeInterval). Without it pacing would make retention converge in 11
DAYS at the daily cadence; with it the worst case converges in ~11 ticks
(~55 min), every burst bounded. 5 min rather than 1 so ticks cannot outrun
the peer's drain and re-accumulate the backlog.
- A ceiling is claimed only when work genuinely remains (bounded EXISTS probe),
so an expired set landing exactly on the budget does not arm a no-op retry.
- Visibility: rate-limited (15 min) Warning naming the ceiling and the
accelerated interval, plus an unthrottled counter
scadabridge.site.event_log.purge_ceiling_hits — its SHAPE distinguishes a
backlog converging from a site whose event rate outruns one paced tick.
- The purge loop is a delay loop rather than a PeriodicTimer, so its cadence
now anchors to the END of the previous purge. Documented.
ROW-33 INTERPLAY VERIFIED: pacing lowers each spike and lengthens total purge
duration, but a full 250k tick drains in ~23 s (~4 min even at 10x a real
link's penalty) against the 15-minute sustained dwell and a 5-minute gap to
the next tick. The UNPACED 2.73M burst had only 2.5x of margin (6.0 min), so
pacing makes the badge assumption robust rather than merely preserving it.
Docs travel together: Component-SiteEventLogging.md, topology-guide.md
("Reading the replication backlog" + the row-33 badge note), CLAUDE.md's
purge-burst sentence, and a dated measurement/decision note under docs/plans/.
Fail-before: the new behavioural tests do not compile against the pre-fix
service (RunPurge was void); with PurgeBudget neutralised to always-unlimited,
6 of the new tests fail and all 19 pre-existing ones pass.
Tests: SiteEventLogging 93/93, Commons 715/715, HealthMonitoring 115/115,
Host 505/505. Solution build clean.
ROW 80 (observability correctness). An unreplicated site published
LocalDbReplicationConnected=false / LocalDbOplogBacklog=0, contradicting the
nullable semantics every doc and the proto already state ("null means no
reading, NOT disconnected with an empty backlog").
Root cause: the replication engine is registered unconditionally and idles
without a peer, so ISyncStatus answers false/0 on a node that was never meant to
replicate, and LocalDbReplicationStatusReporter passed that straight through.
Two consequences: an operator read connected:false on a healthy site as a fault,
and central's null branches — row 33's conditional KPI emission and
sustained-badge anchor exclusion — never received the null they exist for, so
rig site-b/site-c emitted a permanently misleading
localDbReplicationConnected=0 series.
Fix mirrors the SiteEventLogReplicationCheck precedent: the Host evaluates
SiteLocalDbSetup.ReplicationIsConfigured ONCE and passes it to
AddLocalDbReplicationHealthBridge as a third provider; unconfigured
short-circuits the probe to (null, null). HealthMonitoring never reads LocalDb
config itself, and the same captured value now also feeds
SiteEventLogReplicationCheck so the two surfaces cannot disagree.
ISiteHealthCollector.SetLocalDbReplicationStatus widens to bool? — the
non-nullable bool was the type-level root cause (null was inexpressible).
false now means exactly one thing: configured, peer session down = a real fault.
Wire/central/UI needed no change: the proto already carries BoolValue/Int64Value
wrappers and the aggregator + KPI source already branch on null. This makes code
match doc, so no doc claim was weakened.
Watch the trap that caused this: configured-ness is PeerAddress OR ApiKey (only
the dialling half sets a peer address). The pre-existing SiteLocalDbWiringTests
fixture sets ApiKey and IS a replicating node, so its false/0 assertion is
correct and is kept, with a comment saying so; the new
UnreplicatedSiteLocalDbHealthTests fixture is the genuinely-unreplicated one.
ROW 73 (silent loss of self-heal). AkkaHostedService skips
SiteReconciliationActor when no IDeploymentConfigFetcher is resolvable, and that
skip was a lone boot Warning — a node with no self-heal path at all went on
reporting itself perfectly healthy forever.
Adds tri-state SiteHealthReport.StartupReconcilerActive (null = not reported,
i.e. the central self-report or a pre-row-73 site build; true = running;
false = booted without it), latched once at boot by the Host in both branches.
Additive proto field 29 (BoolValue, vendored C# regenerated via
docker/regen-proto.sh centralcontrol; csproj restored, verified empty diff).
The skip branch also raises its log to Error — no configuration makes the
fetcher legitimately absent on a site node — and writes a best-effort
deployment/Error site event so the evidence outlives the boot log.
Central treatment: a "No self-heal" WARNING badge on the site tile, not a
failure. Config still reaches the node via LocalDb replication while it is up;
what it lost is recovery from a deploy that landed while it was down — degraded,
not offline. Only the explicit false is badged (badging null would light up the
whole fleet the moment central is upgraded ahead of the sites), and offline
sites are skipped, matching the replication-backlog badge.
Fail-before evidence: with the row-80 gate behaviourally reverted,
UnreplicatedSite_HealthReport_ReportsNullForBothLocalDbFields fails
"Expected: null / Actual: False" and 3 of the 8 new reporter unit tests fail.
Tests: HealthMonitoring 128, Host 518, CentralUI 1051, Communication 717,
Commons 715, SiteEventLogging 81 — all green.
LocalDbOplogBacklog was reported and Prometheus-exported with nothing consuming
it: not sampled into KPI history, so a purge-burst spike could not be reviewed
after the fact, and no threshold treatment anywhere. Both halves shipped.
KPI SAMPLING. SiteHealthKpiSampleSource now emits localDbOplogBacklog and
localDbReplicationConnected (0/1), and the backlog is charted on the Health
dashboard's per-site trend panel. Charting is the point: a point-in-time tile
can never answer 'did that spike drain?', which is the only thing separating an
expected purge burst from a stalled peer.
Both are CONDITIONALLY emitted rather than coerced with ?? 0 like the
auditBacklogPending metric beside them. Both health-report fields are nullable
and null means 'no reading' — replication not configured (rig site-b/site-c) or
a failed poll — never zero. A fabricated 0 would render a pair that cannot read
its own oplog, or one deliberately unreplicated, as perfectly healthy once a
minute forever, burying the real series. So a site emits 12 metrics when
unreplicated and 14 when replicated, and a GAP in these two series truthfully
means 'not replicated / not reporting'. Note false and null differ for the
connected flag: a configured link that is DOWN samples as 0; no link samples as
nothing. Both fold as Gauge (summing an oplog depth, or a 0/1 flag, per hour is
meaningless).
THRESHOLD SEMANTICS — sustained, not instantaneous. This is the design, not a
refinement. The site_events retention purge is CDC-captured like any other
write, so the backlog jumps by the deleted batch and drains as the peer acks
it; a bare 'backlog > threshold' badge would fire on every replicated site
every day and be ignored within a week. Healthy is defined by the backlog
RETURNING to ~0, which only a dwell can express. CentralHealthAggregator holds
LocalDbBacklogAboveSince — the instant the backlog first rose above
LocalDbBacklogThreshold (default 1000) — and the badge appears only after
LocalDbBacklogSustainedFor (default 15 min). A report at or below the threshold
clears the anchor; one above leaves the ORIGINAL instant intact, so the window
is sustained rather than sliding.
The null case is deliberately a third branch: a null backlog leaves the anchor
UNCHANGED rather than clearing it. Null is evidence neither of a drain nor of a
backlog, so a node going blind mid-climb must not silently reset its own dwell,
and an unreplicated site (null forever) never accumulates an anchor and can
never be badged.
Validation rejects a non-positive threshold (0 would badge every replicated site
permanently, since an idle backlog already sits at it) and a dwell shorter than
one ReportInterval (satisfiable by a single sample, which collapses the check
back into the bare threshold it replaces).
DOC CORRECTION worth flagging: this row's premise was 'mirror the SiteAuditBacklog
configurable threshold badge'. That badge does not exist — Component-HealthMonitoring.md
described it in two places but no option, no comparison and no markup were ever
implemented. The two stale claims are corrected here rather than left to send the
next reader looking for it; the LocalDb badge is built fresh on the Metrics-stale
badge's pattern, which is a real configurable-threshold badge.
Tests: HealthMonitoring 115 (9 new aggregator tests incl. purge-burst-drains,
unreplicated-never-anchors, null-mid-climb, exact-threshold, stale-report; 5 new
validator tests; 4 new sampler tests incl. the null-semantics and false-vs-null
cases); CentralUI 1042 (5 new badge/chart tests incl. the purge-burst negative
control); Commons Kpi 93; KpiHistory 54.
An external system's MaxRetries/RetryDelay existed on the central entity but never
reached a site and had no management surface, so every ExternalSystem.CachedCall
buffered with the S&F engine default (DefaultMaxRetries 50 x DefaultRetryInterval
30s ~= 25 min to park) whatever central had configured. The sibling
DatabaseConnectionArtifact had always carried its equivalents.
The consumption end was already wired: ExternalSystemClient.CachedCallAsync already
read system.MaxRetries/RetryDelay and passed them to EnqueueAsync with the 0-as-unset
convention. Only the transport and persistence were missing.
Commons
- ExternalSystemArtifact gains MaxRetries/RetryDelay as optional positional params
(0 / TimeSpan.Zero = unset), matching DatabaseConnectionArtifact rather than going
nullable, so it maps 1:1 onto the entity and the proto3 scalars.
- Create/UpdateExternalSystemCommand gain nullable MaxRetries/RetryDelay, following
the existing TimeoutSeconds "omit to preserve" convention. Both additive.
Central
- ManagementActor create maps both; update preserves-if-null.
- ArtifactDeploymentService projects them onto the artifact.
Wire
- site_command.proto ExternalSystemArtifactDto gains max_retries=7 /
retry_delay=8 (google.protobuf.Duration), mirroring DatabaseConnectionArtifactDto.
Additive: a pre-existing site decodes them as 0/absent, which IS the unset value,
so old behaviour is preserved. Vendored C# regenerated via docker/regen-proto.sh
sitecommand; csproj Protobuf item re-commented, no message types added or removed.
Site
- external_systems gains max_retries / retry_delay_ms via AddColumnIfMissing,
DEFAULT 0 = unset. Storage upsert, repository SELECT/mapping (new ordinals 6/7
appended so existing ones are untouched), apply path, and the legacy migrator's
explicit column list all carry them.
Replicated-table decision: external_systems IS in SiteLocalDbSetup.ReplicatedTables,
so this was checked against the AckTime/native_alarm_state precedent. Real columns
are correct here, not a JSON bag: the table has no general-purpose config column
(auth_configuration and method_definitions are both semantically specific),
timeout_seconds already set the additive-column precedent on this exact table, and
sibling database_connections stores the same two values as plain columns. Verified in
LocalDb source that RegisterReplicated re-reads PRAGMA table_info every boot and its
install script is DROP-then-CREATE, so capture triggers rebuild over the new column
set automatically, and SiteStorageSchema.Apply runs before registration on the same
boot. The only cost is the ReplicatedTable.ComputeDigest change, which the sync
handshake compares fail-closed - a mixed-version pair refuses to sync loudly instead
of diverging silently. Both-nodes-together is already the standing site-pair rule, so
no new operational constraint; recorded in topology-guide.md.
Also fixed: ArtifactDiff.CompareExternalSystem never compared MaxRetries/RetryDelay,
so a bundle import that changed a system's retry budget previewed as "Identical" -
harmless while the values were inert, a live behaviour change now.
No EF migration: the central ExternalSystemDefinitions columns already exist
(InitialSchema). Central UI already had both form fields.
Tests: site storage round-trip + unset-default, site apply path, central artifact
projection, proto round-trip (via the shared sample), management create/preserve,
CLI option parse + alias, and diff reporting. Fail-before verified on the two core
tests (expected 7 got 0 on the read path; expected 9 got 0 on the apply path).
Docs: Component-ExternalSystemGateway, Component-StoreAndForward, Component-CLI,
components/StoreAndForward, components/SiteRuntime, deployment/topology-guide,
CLI README (which was also missing --timeout-seconds entirely).
scadabridge_site_connection_up never counted data connections. It counts open
central->site gRPC subscriber streams (Debug View + the site-wide alarm feed),
so it correctly reads 0 on a healthy site nobody is watching — and the name
invited reading it as device health. That misreading has already cost a live
debugging session: register row 48's 'connection_up is 0 on all six site
nodes' was healthy steady state, not the fault it was diagnosed as.
Two halves, per the row:
RENAME. scadabridge.site.connection.up -> scadabridge.site.stream.subscribers.active
(helpers SiteConnectionOpened/Closed -> SiteStreamSubscriberOpened/Closed), and
the instrument gains the unit:"1" the other gauges already carried. Every
reference updated: the gRPC server, both test suites, Component-Communication.md,
components/Commons.md, docker/README.md and docker/seed-live-probe.sh. A test
now pins the new name AND asserts the old one is gone, so it cannot creep back.
NEW. scadabridge.site.data_connections.connected / .total — the first exported
data-connection signal (the state existed on the health report and in the CLI,
but never as a metric). connected < total is the alert condition; neither
number alone separates 'a device is down' from 'nothing is configured', which
is why the denominator ships with the numerator.
Sourcing is deliberate on two counts. It is fed by the DCL at its four state
transitions rather than derived from the health report, so the metric survives
a dead report pipeline — the exact failure the 'metrics stale' flag exists to
catch, and a derived gauge would go blind at the same moment. And it uses a
static registry reached through ScadaBridgeTelemetry (the SiteConnectionOpened
precedent) rather than a DI-injected holder: the DCL actors already take
ISiteHealthCollector through their constructors, and threading a second
dependency through both would ripple into every test that builds them. It also
keeps SiteHealthCollector untouched, which matters right now — another agent is
concurrently editing that file for the tag-resolution path.
Removal is wired too: an undeployed connection leaves the registry, so it stops
counting toward the total instead of latching connected < total on forever.
Both gauges read 0 on the standby (connections open on the active node only) —
healthy, documented, and called out in the docs so it does not become the next
site_connection_up.
No ObservedMeters allowlist change: all three instruments ride the existing
ZB.MOM.WW.ScadaBridge meter. (An unlisted meter exports nothing, silently.)
Tests: Commons 711 passed (9 new, delta-based against a baseline with unique
per-test connection names, so they do not inherit the register row 32
QueueDepthGaugeTests static-state flake); Communication 717; DCL 319.
SiteReconciliationActor's node-STARTUP fetch healed the config FILE but never the
RUNTIME. Instance Actors are created from exactly two paths -- the Deployment
Manager's boot-time SQLite load and an explicit deploy/enable command -- and the
reconcile pass runs AFTER that boot load has already read storage. So a config
reconcile restored started no actor: an enabled, successfully-deployed instance
whose config was missing at boot (lost volume, first boot after a restore,
rehomed data dir) stayed dead until the NEXT restart, whose load finally picked
it up. Proven live on site-a 2026-08-15: "Reconcile: fetched + stored config"
with no "InstanceActor started" after it, and a debug snapshot answering
instanceNotFound.
The pass now raises a fire-and-forget EnsureInstanceStartedCommand (new Commons
Deployment message) for every ENABLED instance it healed, routed through the
deployment-manager singleton PROXY so Instance Actors stay under the singleton no
matter which node's reconcile found the gap.
The handler is deliberately advisory:
- idempotent -- no-op when the actor is already running, which both nodes'
reconcile actors legitimately trigger for the same instance;
- enabled-state-aware -- it re-reads the durable row, which is the authority on
both the config body and enabled/disabled, so a disable landing after the
fetch still wins and the instance stays stopped;
- it defers to any in-flight deploy/redeploy/warm for the instance, which keeps
the deploy gate's ordering guarantees and the all-or-nothing-per-instance rule
intact -- this never applies a config, it only starts one already persisted;
- a missing row is a quiet no-op, the normal case on an unreplicated site whose
peer node healed its own file.
The heal is no longer silent: a successful reconcile start emits a Warning log
line and an operational `deployment` site event, because reaching it means the
node booted without a config for an instance that should have been running.
Row 53 shipped the scadabridge.central.transport.import_sessions.open gauge
and a Warning log on a cap hit, but a log line is not something an operator
can alert on. Adds the companion counter
scadabridge.central.transport.import_sessions.rejected
on the existing ZB.MOM.WW.ScadaBridge meter, so no ObservedMeters allowlist
change is needed (an unlisted meter exports nothing, silently).
The emit point is deliberately narrow. BundleSessionStore.Open tests the cap
TWICE — once on entry and again after EvictExpired() — and only the second
test is a rejection: a store full of merely expired sessions reclaims a slot
and admits the caller. Counting the first would make the series fire
routinely on any node whose sweep had not yet run, turning a page-worthy
signal into background noise. Re-Opening an already-open session id skips
the cap block entirely and is likewise not counted.
The two instruments are diagnostic as a pair: rejections rising while the
gauge oscillates below the cap is genuine concurrency (raise the cap);
rejections rising while the gauge sits pinned at the cap is a session leak
(register row 43's signature), where raising the cap only defers the problem.
Tests assert a delta over a scoped action rather than an absolute value, so
they do not inherit the register row 32 static-state flake that makes
QueueDepthGaugeTests fail only under the full concurrent suite. Negative
controls cover under-cap, expired-reclaim, and duplicate-session-id.
Tests: 11 passed in BundleSessionObservabilityTests (6 existing + 5 new).
The per-IP unlock throttle's counters were a process-local ConcurrentDictionary
on each central node, so the effective fleet cap was N x
MaxUnlockAttemptsPerIpPerHour per client (failing over to the other node handed
the client a fresh budget) and a node restart cleared the window outright.
The window now lives in the central MS SQL BundleUnlockAttempt table — the HA
store both central nodes already share, so no new infrastructure, no new port,
no consensus protocol:
- Commons: BundleUnlockAttempt entity + IBundleUnlockAttemptRepository.
- ConfigurationDatabase: entity config (one index,
IX_BundleUnlockAttempt_Client_Attempted, serving both the windowed count and
the prune), repository (AsNoTracking count, ExecuteDeleteAsync prune),
DbSet, DI registration, migration AddBundleUnlockAttemptTable + the
hand-written idempotent production script under docs/plans/sql/.
- Transport: IBundleUnlockAttemptWindow seam + SqlBundleUnlockAttemptWindow
(singleton; resolves the scoped repository from its own scope per call, like
the central purge singletons). BundleUnlockRateLimiter keeps the policy and
gains TryRegisterAttemptAsync; BundleImporter.LoadAsync calls it.
Behaviour preserved from row 44: locked bundles spend no hourly budget (the
lockout check still runs first), throttle denials burn no per-bundle strike and
are NOT recorded so they cannot roll the window forward, unattributable clients
share the stricter <unattributed> bucket, and the budget counts attempts rather
than failures. Config keys and their semantics are unchanged, so the rig's 500
override stays valid.
Three deliberate trades, documented in both Transport docs:
- FAILS OPEN. A store error logs a Warning naming the client and cap, and
permits the attempt. This is a best-effort rate cap over an already
authenticated, Administrator-gated surface — the availability of legitimate
imports outranks the cap, and a DB blip must not make the import wizard
unusable. Falling back to the process-local window was considered and
rejected: it would still block a legitimate operator's 11th import.
- Approximate. Count-then-insert is not atomic across nodes, so simultaneous
attempts can overshoot by the number in flight — bounded, self-correcting
within the window, and not worth provider-specific raw SQL.
- Pruned opportunistically on the unlock path (CAS-claimed at most every 15
min per process, bounded to 1000 rows, retaining 2x the window, best-effort
try/catch) rather than by a new background service — Transport owns no
central scheduler. Same shape as DeploymentService's terminal-record sweep.
Tests: Transport.IntegrationTests 116 passed (+10 — two limiter instances over
one store enforcing a single combined window, restart durability, denials
burning no budget, sliding release, bucket isolation, store-failure fail-open,
caller-cancellation not swallowed, no-shared-window fallback, prune and its
negative control); ConfigurationDatabase 395 passed (+5).
Nothing counted open import sessions and nothing logged a rejection at
MaxConcurrentImportSessions (default 8), so the register-row-43 session leak
could only be inferred from rotating test failures.
- Gauge scadabridge.central.transport.import_sessions.open on the existing
ZB.MOM.WW.ScadaBridge meter — already in SiteServiceRegistration.ObservedMeters
(the ZbTelemetryOptions.Meters allowlist), so no telemetry config change is
needed and the series is not silently dropped. Provider-backed, mirroring the
StoreAndForward queue-depth gauge: registered by BundleSessionEvictionService
.StartAsync (Transport's only lifecycle seam) and identity-checked-cleared on
StopAsync so a late stop cannot clobber a newer registrant.
- IBundleSessionStore.OpenSessionCount counts only UNEXPIRED sessions. The raw
dictionary count would report the node as pinned at the cap for up to a
one-minute sweep interval after a burst had drained — the exact false positive
the instrument exists to rule out.
- BundleSessionStore.Open logs Warning with open count, cap and TTL when it
rejects. Fires only on a real cap hit: a store full of expired sessions is
reclaimed first and logs nothing.
- Docs: docs/components/Transport.md + docs/requirements/Component-Transport.md.
Tests: Transport 173 passed (+6 new — Warning content, two negative controls,
unexpired-only counting, gauge register/clear, no-clobber-on-late-stop).
Deferred-work register row 46. HandleQueryAuditLog returned ICentralUiRepository's
(IReadOnlyList<AuditLogEntry> Entries, int TotalCount) ValueTuple straight to
ManagementActor.SerializeResult. System.Text.Json writes properties only, and a
ValueTuple exposes Item1/Item2 as public FIELDS, so the whole payload serialized to
the literal "{}" — the CLI faithfully printed an empty object no matter how many
AuditLogEntries rows matched, with no error anywhere in the stack.
Fixed at the handler (the layer that leaks the tuple), not the CLI: new Commons record
AuditLogQueryResult(Entries, TotalCount), mirroring the SecuredWriteListResult shape
already used by the other paged management query.
Also guards the whole class of bug: SerializeResult now throws on any ITuple result,
so the next handler that returns a tuple fails loudly instead of silently emitting {}.
Tests (fail-before verified — the query test asserted exactly "{}"):
- QueryAuditLogCommand_ReturnsEntriesAndTotalCount
- SerializeResult_TupleResult_ThrowsInsteadOfEmittingEmptyObject
- SerializeResult_AuditLogQueryResult_EmitsEntriesAndTotalCount
Docs: Component-CLI.md + CLI README document the response shape and why it is a record.
ManagementService references Commons but not Transport, so MapFault could not
see BundleLockedException and the per-bundle 3-strike lockout reached the CLI
as "An internal error occurred (CorrelationId=...)" — the operator got a
correlation id instead of the reason, and no hint that further attempts on
that bundle would be refused.
Applies the pattern register row 44 established for BundleUnlockThrottledException:
- Relocate BundleLockedException from Transport/Import/ to
Commons/Types/Transport/, beside BundleUnlockThrottledException. Both
consumers (BundleImporter, CentralUI TransportImport) already carried the
Commons.Types.Transport using, so no call-site edits were needed.
- Add curated catch arms in ManagementActor.HandlePreviewBundle and
HandleImportBundle that rethrow as ManagementCommandException, so the
message survives MapFault's disclosure filter.
- Mirror the row-44 throttle fault-mapping test for both handlers.
- Document the relocation in docs/components/Transport.md and
docs/requirements/Component-Transport.md.
Tests: ManagementService 499 passed (+2 new), Transport 167 passed.
BundleUnlockRateLimiter was registered (ServiceCollectionExtensions), injected
into BundleImporter, unit-tested, documented on
TransportOptions.MaxUnlockAttemptsPerIpPerHour = 10 and pinned in
appsettings.Central.json — but _unlockRateLimiter was never invoked. A
brute-force passphrase attacker against a stolen bundle was bounded only by the
per-bundle 3-strike lockout, which a re-export side-steps (new ContentHash).
LoadAsync now registers every unlock attempt against the limiter. Ordering is
load-bearing: AFTER the per-bundle lockout check (hammering a locked bundle
spends no hourly budget) and BEFORE the decrypt (so a denial burns no per-bundle
strike — otherwise the throttle would be a way to lock a bundle someone is
legitimately importing). Over budget throws the new
BundleUnlockThrottledException, fail-closed with a clear message on both
surfaces; it lives in Commons because the management surface (Commons-only
references) must catch it to return a curated error rather than MapFault's
generic internal-error text.
Client key plumbing:
- Central UI: new scoped CircuitClientAddressProvider snapshots
Connection.RemoteIpAddress at circuit establishment — the same constraint and
the same pattern as CookieAuthenticationStateProvider, since HttpContext is
null by the time a circuit submits a passphrase.
- CLI/management: additive ManagementEnvelope.ClientIp, stamped by
ManagementEndpoints and threaded through DispatchCommand to the preview/import
bundle handlers.
- No attributable address => a single SHARED "<unattributed>" bucket, not a
bypass: unknown clients get a stricter budget, never none. Per-client
isolation is only real behind a ForwardedHeaders-trusted proxy, the same
caveat the login throttle carries (Component-Security.md).
Docs: Component-Transport.md + docs/components/Transport.md record the two-level
ordering, the client-key sourcing, the shared-bucket fallback and a
troubleshooting entry for the new error.
Tests: 6 importer tests (cap enforced; denial != passphrase failure, no strike
burned; per-client isolation; shared unattributed bucket; unencrypted bundles
consume no budget; a locked bundle spends no hourly budget) — 4 of the 6 fail
with the limiter call disabled, i.e. against the dead-code state. Plus
ManagementActor tests pinning the ClientIp forwarding and the curated
throttle error.
Only BundleImporter.ApplyAsync released an import session, so every path that
opened one and did NOT apply held one of MaxConcurrentImportSessions (8) — and
the DECRYPTED bundle content that T-007 deliberately zeroes on the apply paths —
for the full BundleSessionTtlMinutes (30). Eight abandonments locked out all
imports on the active node; observed live (R6: 3 back-to-back suite runs held 6
of 8 slots until central-b was restarted).
New IBundleImporter.Abandon(sessionId): the same zero-then-remove release
ApplyAsync performs, idempotent (double release / unknown id / expired id are
no-ops) and only ever given the random-GUID id its caller opened, so it can
never evict another circuit's session.
Wired into every abandonment path:
- Central UI wizard — ReleaseSession() from new upload, TryLoadAsync (before it
overwrites _session), Back-to-Upload / ResetSessionState, the 3-strike lockout
reset, and Dispose (navigation away / circuit teardown).
- CLI transport preview — a preview never applies, so nothing released it at
all; now released in a finally.
- CLI transport import — covers the pre-apply aborts (blocker rows, unresolved
site/connection mappings).
Class doc's "an abandoned wizard does not leak" claim is true again (it only
ever covered the staged plaintext temp file). Component-Transport.md +
docs/components/Transport.md now record the explicit-release contract and that
BundleSessionEvictionService is a TTL backstop, not an abandonment path.
Tests: 4 bUnit tests over a REAL BundleSessionStore (dispose / back-to-upload /
apply-then-dispose idempotency / concurrent-circuit isolation) — 3 of the 4 fail
against the pre-fix page; 4 importer tests (release + zeroing, idempotency,
cross-session isolation, and the slot-cap regression).
Every AttributeValueChanged/AlarmStateChanged rode its own gRPC message on
SiteStreamService; at target scale that is ~37.5k messages/s/site of pure
framing overhead. Coalesce them, additively, with no new RPC.
Wire (sitestream.proto, regenerated via docker/regen-proto.sh sitestream):
InstanceStreamRequest.batching_supported = 3
SiteStreamRequest.batching_supported = 2
SiteStreamEvent.batch = 4 (new oneof case)
SiteStreamEventBatch { repeated SiteStreamEvent events = 1 }
The proto3 default of batching_supported IS the negotiation, and it is
load-bearing: a batch frame reaches a pre-R2 central as EventOneofCase.None,
whose ConvertToDomainEvent returns null — the whole batch would vanish with
no error anywhere. An old central cannot set the flag so it never receives
one; an old site ignores the unknown request field and keeps sending
per-event frames, which the new client's ForEachEvent handles as the
single-event case. Both skew directions are covered by tests that go through
a real proto serialize/parse round-trip.
Server: SiteStreamEventBatcher, a per-subscriber pump replacing the handler's
await-foreach/WriteAsync loop and byte-identical to it at a cap of 1. It
never delays a lone event — it drains the already-queued backlog for free and
lingers only once a backlog is proven — emits a single-event buffer as a
plain frame, preserves order and per-event Timestamps exactly, and flushes
what is buffered when the send channel's writer completes. It sits DOWNSTREAM
of StreamRelayActor's bounded DropOldest channel, so it changes framing only
and does not move the burst ceiling (deferred register row 31, which lives in
the shared publish stage upstream of the BroadcastHub).
Client: sets the flag on both subscriptions and unpacks in order into the
existing per-event pipeline, so SiteAlarmAggregatorActor,
DebugStreamBridgeActor, consumer-keepalive/orphan logic,
reconnect-on-graceful-completion, generation fencing, the (siteId, endpoint)
factory key and IsLive semantics are untouched.
Options (validated): GrpcStreamBatchMaxEvents 100 (1 disables),
GrpcStreamBatchWindow 25 ms — validated strictly under 250 ms, the load
test's end-to-end P99 threshold. Measured worst case (trickle-with-backlog,
window-bound rather than cap-bound): P50 13.8 ms, P99 25.4 ms, max 25.8 ms;
cap-bound case sent 600 queued events in 6 frames.
Telemetry: histogram scadabridge.site.stream.batch_size tagged by stream
kind, recorded only on negotiated streams (per-event otherwise). It rides
ScadaBridgeTelemetry.MeterName, already in the ObservedMeters allowlist.
Docs: Component-Communication.md gains an Event Batching section; CLAUDE.md's
gRPC streaming bullet records the wire shape and the negotiation rationale.
The Deployment Status page client-materialized the whole deployment list. It read
EVERY DeploymentRecord — an insert-only table, one row per deploy attempt for the
retention window — plus EVERY Instance, then site-scoped, sorted, counted the four
status tiles and sliced a 25-row page in the Blazor circuit's memory. That ran on
first render AND on every IDeploymentStatusNotifier push, so the cost scaled with
the age of the system rather than the size of the page.
All four jobs move into SQL:
- `IDeploymentManagerRepository.QueryDeploymentListPageAsync(filter, page, size)`
returns one page of `DeploymentListRow` — DeploymentRecord INNER JOINed to
Instance, so the instance display name and site travel with the rows that need
them — plus the total count of the filtered set. The join is exact: the FK is
Restrict and DeleteInstanceAsync removes the records first, so no orphan exists.
- `GetDeploymentStatusCountsAsync(filter)` returns the tile counts from ONE grouped
aggregation, deliberately ignoring the filter's Status: the tiles are the status
BREAKDOWN of the filtered set, so honouring it would zero three of four tiles the
moment an operator clicked one.
- Site scoping runs in the query as `SiteIdScope` resolved through the record's
instance (DeploymentRecord has no SiteId of its own). An EMPTY grant stays a real
filter matching nothing, never "unconstrained".
- The now-callerless whole-table `GetAllDeploymentRecordsAsync` is deleted.
OFFSET paging, not the Audit Log's keyset cursor, and deliberately so: this page's
pager is numbered and jump-to-any-page, so it needs a page count, which only a total
can give it — a keyset cursor can express neither, and the total is required for the
tiles regardless. The deep-offset cost that pushes high-volume tables to keyset is
bounded here by the terminal-record retention purge, unlike the 365-day AuditLog.
This mirrors the Notification Outbox, offset-paged for the same reason. Ordering is
DeployedAt DESC, Id DESC — the Id tie-break is load-bearing, because DeployedAt ties
on rapid redeploys and an unstable sort key makes offset paging repeat or drop rows.
UI: the four status tiles become the status filter (click to apply, click again to
clear, aria-pressed, phrasing-only content so a <button> stays valid), plus a
free-text search matched DB-side against instance name, deployment id, revision hash
and initiating user. Search is TRAILING-edge debounced at 500ms — the same Timer +
lock + _disposed idiom as the existing leading-edge push coalescer, minus the leading
edge, because a search box must not query on the first keystroke. A filter change
resets to page 1; a page past the end falls back to the last real page. Bootstrap
only, existing PagerWindow pager retained.
The WP2.4 push coalescing is unchanged and still earns its keep: server paging shrank
what a reload costs, not how many arrive — it now bounds database round-trips rather
than table scans.
Tests: 19 new SQLite repository tests (paging slice + total, tie-break stability
across pages, page/size clamping, past-the-end, the joined projection, every filter
dimension incl. the empty-scope security case, and the grouped counts' status-blind
contract); 15 new bUnit page tests (page-1 request, server total drives the pager,
Next re-queries, tiles show server counts not page counts, tile filter + toggle,
system-wide vs site-scoped scope push, debounce collapses a keystroke burst to one
query, clear-filters, dispose with an armed timer). The two existing Deployments
suites re-point their reload assertions at the new query.
Doc: Component-CentralUI.md Deployment section — the "no server-side paging" known
residual is replaced by the shipped design.
F1 (HIGH) DebugStreamBridgeActor: the 5-minute orphan net measured the MAILBOX
(SetReceiveTimeout), and once stream events were correctly marked
INotInfluenceReceiveTimeout nothing recurring reset it — the snapshot lands once
and GrpcStreamStable once — so every healthy session self-terminated at ~6 min
with a false "Site disconnected". Replaced with a periodic self-tick
(ConsumerLivenessCheckInterval, 30s) over a consumer-last-seen stamp renewed only
by DebugStreamConsumerAlive, which DebugStreamService Tells on a shared timer to
every session still in its registry (holding a session there IS "a consumer is
attached" — both the Blazor view and the SignalR hub release it on
dispose/disconnect, and it works headless). Reverting the wrapper was rejected: it
would restore the quiet-instance orphan bug.
F2 (MED) SiteStreamGrpcClient: the RpcException(Cancelled) filter now requires
cts.IsCancellationRequested. A peer-originated / channel-dispose Cancelled fired
none of onError/onCompleted/onConnected, leaving SiteAlarmAggregatorActor with
_streamDown=false forever (IsLive stuck true, reconcile reopen guard never fired).
F3 (MED) SiteStreamGrpcClient: a header TIMEOUT is no longer reported as
connected — that shape is exactly what an unreachable site produces, and it
cleared _streamDown, consumed _seedOnConnect and launched a full snapshot fan-out
at a dead site. AwaitHeadersAsync returns bool; the first received event is the
fallback connected signal, fired at most once from headers OR first event.
F4 (LOW-MED) SqliteAuditWriter.MarkReconciledUpToAsync: the blanket below-cursor
UPDATE retired late-stamped inserts that were never served (then age-purged —
silent loss). The flip is now bounded by insertion order: a Pending row retires
only if its rowid is at or below the high-water mark of rows this instance has
served from ReadPendingSinceAsync (clamped on purge, since SQLite reuses rowids);
Forwarded rows are exempt (central ACKed them over the push path). At-least-once
is unchanged.
F5 (LOW) Documented the liveness dependency (a served row never covered by a later
cursor stays Pending forever; PurgeExpiredAsync never purges Pending) in
ISiteAuditQueue + Component-AuditLog.md, and added a cheap site-health signal:
SiteAuditBacklogReporter logs a rate-limited warning when the existing
oldest-pending metric exceeds 24h.
F6 (MED) SiteAlarmAggregatorActor: _fanoutSinceLastTick was armed by the
reconcile's OWN fan-out, so steady state ran fan-out→skip→fan-out→skip — one
reconcile per 2x interval (120s), halving the not-reporting refresh and the alarm
reconcile backstop. The skip is now armed only by connect/failover-driven seeds
(initial, _seedOnConnect, and a re-seed queued behind one).
Tests: Communication.Tests 691 passed (+13), AuditLog.Tests 382 passed (+5).
Six adversarial-review findings in the central SQL/ingest layer.
F1 (AuditLogRepository.InsertChunkAsync) — the set-based ingest declared each
string parameter at its COLUMN width (Actor/Target 256, Action 64, Outcome 16,
Category 32, SourceNode 64), so SqlClient truncated an over-long value at bind
time and committed the mutilated row — silent, in an append-only store, with no
PayloadTruncated flag — while the per-row and reconciliation paths sent the same
value in full and let the server reject it with 2628. Bind at the value's own
length instead; explicit SqlDbType is kept (it fixes the VALUES constructor's
derived column types and datetime2 precision). Design: reject everywhere,
truncate nowhere — matching today's per-row behaviour.
F2 (SiteCallAuditRepository.UpsertAsync) — the single-statement upsert ran the
monotonic UPDATE first and INSERTed only if nothing matched. Two writers racing
the first packet of one TrackedOperationId (the cached dual-write and the
reconciliation pull carry DIFFERENT lifecycle states) both matched nothing, and
the loser then skipped its INSERT or swallowed a 2627 — dropping its
Status/RetryCount/HttpStatus/TerminalAtUtc. Legs swapped to
`IF NOT EXISTS … INSERT; UPDATE <monotonic>` — still one round trip, and the
loser's UPDATE now lands on the winner's row. The duplicate-key catch re-runs
the monotonic UPDATE for the same reason. Moved to raw SQL with explicitly-typed
parameters so the intricate rank predicate exists in exactly one place (an
untyped DateTime would bind as `datetime` and round the freshness tiebreaker).
F3 (docs/plans/sql/*.sql) — filtered-index DDL failed with error 1934 under the
documented `docker exec … sqlcmd` path, which defaults QUOTED_IDENTIFIER OFF;
once IX_Notifications_Delivered exists, QI-OFF DML on Notifications fails too.
All four scripts now open with `SET QUOTED_IDENTIFIER ON; SET ANSI_NULLS ON; GO`
(own batch, so it is in force when the next batch parses), and the migration
convention in Component-ConfigurationDatabase.md documents `sqlcmd -I`. Verified
live: the pre-fix script fails 1934 without -I, the fixed one applies.
F4 (SiteCallAuditActor) — the off-mailbox reconciliation/purge passes reuse the
injected repository, so tests drove one DbContext from the pass and a mailbox
handler concurrently. Serialized at the CALL via a private SerializedRepository
wrapper applied only by the test constructors, rather than running the pass
on-mailbox: production keeps its PipeTo shape untouched, and the existing
"a blocked drain does not stall ingest/query/KPI" regression tests stay
meaningful (they would have been invalidated by suspending the mailbox).
F5 (AuditLogIngestActor) — when the batch failed because the 20 s IngestBudget
expired, the per-row fallback reused the same expired token: N instant failures,
N counter bumps, zero accepted. The fallback now gets a fresh 5 s budget (inside
the 30 s outer Ask), and a blown budget bumps the failure counter ONCE for the
batch instead of once per row.
F6 (NotificationOutboxRepository.UpdateAsync) — ExecuteUpdate's row count was
discarded, so an operator Retry/Discard of a notification the retention purge had
already deleted reported success (the pre-ExecuteUpdate code threw
DbUpdateConcurrencyException). UpdateAsync now returns whether a row matched; the
operator one-shots answer "notification not found" and emit no audit row for the
action that did not happen, while the dispatcher logs a warning (its delivery
already happened; nothing to retry). GetByIdAsync switched to AsNoTracking since
the write is out-of-band.
Tests: 5 new SQL-backed regressions (over-long Target rejected on both paths +
boundary round-trip; concurrent first-write and already-created-by-another-writer
upserts; vanished-row UpdateAsync), a token-identity pin on the ingest fallback,
a repository-concurrency detector for the SiteCallAudit passes, and vanished-row
operator-path tests. The F1/F2/F4 regressions were each confirmed failing against
the pre-fix code. Suites: ConfigurationDatabase 369, AuditLog 378, SiteCallAudit
66, NotificationOutbox 152 — all green, solution builds with 0 warnings.
WP2.6 (arch-review remediation, cross-cutting misc):
- SiteExternalSystemRepository: name/ID-indexed ExternalSystemDefinitionCache replaces
the fetch-all + reverse-map scan on every by-ID/method lookup; loaded once per
redeploy, invalidated by DeploymentManagerActor after HandleDeployArtifacts applies
external-system changes. Static JsonSerializerOptions for method-list parsing.
- Inbound API: short-TTL ApiMethodCache fronts the per-request ApiMethod repository
fetch; invalidated by name via the existing ScriptArtifactChangeSubscriber/
IScriptArtifactChangeBus pipeline, self-healing via TTL for changes the bus
doesn't cover (e.g. Management API edits).
- StoreAndForward: the cached-call audit-observer queue — the one unbounded channel
left in the system — is now bounded (ObserverQueueCapacity, default 10,000) with
DropOldest overflow and a dropped-notification counter.
- SiteStreamManager: alarm state changes now travel a dedicated publish
source/broadcast hub, isolated from the (far higher-volume) attribute path, so an
attribute storm can no longer evict a pending alarm transition; the alarm hand-off
queue is bounded with a drop counter surfaced on the site health report
(SiteStreamAlarmDropCount via the new SiteStreamAlarmDropReporter), and publishing
is skipped entirely at zero subscribers on either path.
- CLI ManagementHttpClient: explicit 30s HttpClient.Timeout on the shared
construction (was the 100s framework default), overridable via
SCADABRIDGE_HTTP_TIMEOUT_SECONDS.
Deviation: the failback-probe heartbeat item is NOT included — its only viable
surface (CentralChannelProvider.cs / heartbeat consumers) lives entirely in the
Communication project, explicitly off-limits to this work package this phase.
Tests: SiteRuntime.Tests (550), InboundAPI.Tests (278), StoreAndForward.Tests (133),
CLI.Tests (390), HealthMonitoring.Tests (97) — all green after full solution build.
MES alarm-status API §5.2 (docs/plans/2026-06-30-mes-alarm-status-api.md,
Phase 1 tasks 2-4). Site `Call` scripts had NO way to read alarm condition
state: the `Alarm` global exists only inside an on-trigger handler and
describes the one alarm that fired, and native mirrored conditions were
reachable only from the Debug View. That gap blocked the CvdReactor
SimpleAlarmStatus/AlarmStatus scripts entirely -- they cannot be written
without it. `Alarms.CurrentAsync()` closes it.
The data was already local: the script runs inside its own Instance Actor's
context, so this is a LOCAL Ask -- the same mechanism attribute reads use, no
cross-cluster hop. A dedicated GetAlarmSnapshotRequest/Response is used rather
than reusing DebugSnapshotRequest, which would materialise every attribute
value on every alarm poll; both are served from the same
BuildAlarmStatesSnapshot(), so the script view and the operator's Debug View
can never disagree.
Deliberate shape decisions:
- NOT scope-prefixed, unlike Attributes. Alarm identity is not a
scope-relative attribute name (computed alarms are keyed by configured
name, native conditions by a source-supplied reference), so prefixing
would hand a composed script a silently truncated list.
- Read-only. Native alarms are a read-only mirror of the source (no
ack-back), so no acknowledge/shelve operation is exposed.
- Placeholder rows are NOT pre-filtered: a caller must be able to tell
"binding configured and quiet" from "binding unknown". The documented
filter is `Active && !IsConfiguredPlaceholder`.
- ScriptAlarm lives in Commons so the runtime accessor and the compile-only
surface project to the SAME type -- a script binding at the design-time
gate binds identically at the site. Condition is the authority for
active/acked/severity, so one filter expression works across computed and
native alarms.
Mirrored on BOTH design-time surfaces. ScriptCompileSurface is covered by the
reflection parity guard (AlarmsAccessor added to its mirror pairs). The Central
UI Test-Run SandboxScriptHost is the third, hand-maintained mirror that the
parity test cannot reach (Central UI does not reference Site Runtime); without
it the design page would false-flag CS1061 on scripts the deploy gate accepts.
It throws a labelled ScriptSandboxException at run time -- there is no central
route to per-instance alarm state, and returning an empty list would read as
"nothing is in alarm", which is worse than an error.
ScriptTrustPolicy needs NO change, and the reason is structural rather than
incidental: the trust boundary is a deny-list over API roots, not an allow-list
of context members. A test pins that no ForbiddenScopes entry prefixes the
Commons script-surface namespace, so a future deny-list entry cannot silently
make ScriptAlarm untouchable.
Tests: 6 accessor cases (Ask contract, full native projection incl. AckTime,
unacked, computed-alarm derivation, placeholder visibility, scope-independence),
2 InstanceActor snapshot cases incl. equality with the Debug View row set, the
full MES script shape compiling against ScriptCompileSurface, 2 trust cases,
and a sandbox diagnose-clean case reading every projected ScriptAlarm field.
MES alarm-status API §6.4 (docs/plans/2026-06-30-mes-alarm-status-api.md,
Phase 1 task 1). MES needs a real AckDT for a triggered alarm, and the mirror
carried acked-vs-unacked but never WHEN. AckTime now rides the whole path:
DCL transition -> AlarmStateChanged -> gRPC AlarmStateUpdate -> site SQLite.
Stamping rule, identical on both protocols: non-null ONLY while the condition
is active AND acknowledged. That single predicate yields all three required
behaviours -- null while unacked, cleared on re-raise (a re-raise arrives
unacknowledged), and no phantom ack on a return-to-normal. The last one is
load-bearing for MxGateway, which maps INACTIVE to Acknowledged = true; without
the active check every clear would claim an ack the system never observed.
Provenance is honest, never fabricated:
- OPC UA A&C supplies a TRUE ack instant, so we now select it:
AcknowledgeableConditionType/AckedState/TransitionTime at SelectClause
index 18, APPENDED so the positional reads at 0-17 keep their meaning.
Servers that omit the field fall back to the event's own Time.
- MxAccess Gateway supplies none, so the ack transition's own timestamp is
used -- accurate to when the system SAW the ack. An ACTIVE_ACKED
re-subscribe snapshot restores one from LastTransitionTimestamp rather
than dropping it.
The decision lives in pure mappers (Opc/Mx AlarmMapper.DeriveAckTime), so it is
unit-tested with no live server or gateway.
Additive-only throughout: init-only property on AlarmStateChanged, trailing
optional positional on NativeAlarmTransition (all 14-arg call sites untouched),
proto field 24 (never reusing a number) regenerated via docker/regen-proto.sh
sitestream with the csproj diff verified empty.
Persistence rides native_alarm_state's existing metadata_json blob rather than
a new column -- deliberately. That table is RegisterReplicated in
SiteLocalDbSetup and LocalDb builds its CDC triggers from the column list at
registration time, so an additive JSON property changes no schema, no triggers
and no replication contract; metadata_json is exactly the extension point UA4
introduced for this. Rows written before the field deserialize it as null.
Tests: 4 OPC UA + 6 MxGateway mapper cases, 3 NativeAlarmActor (emit,
failover rehydrate, pre-AckTime row), 1 proto round-trip incl. the null case,
4 Commons additive/back-compat. The OPC UA SelectClause count lock-in moves
18 -> 19 with an index-18 assertion -- intended, the clause is appended, which
is precisely what that guard exists to make visible.
M5.4 T4 threaded a `parentExecutionId` parameter through
AlarmActor.SpawnAlarmExecution → AlarmExecutionActor → ScriptRuntimeContext,
but every call site passed null — so alarm on-trigger runs were silently always
execution-tree roots, contradicting the "tag-cascade coverage is complete"
claim in CLAUDE.md and Component-AuditLog.md.
Source the id where a spawner genuinely exists: a static attribute write issued
by a site script (`Instance.SetAttribute`) or by an inbound API request
(`Route.To(...).SetAttributes(...)`, whose ParentExecutionId was already carried
to the site and then dropped). The id rides site-locally through three additive,
nullable fields — no wire, proto or central schema change:
ScriptRuntimeContext.SetAttribute / RouteToSetAttributesRequest.ParentExecutionId
→ SetStaticAttributeCommand.SourceExecutionId
→ AttributeValueChanged.SourceExecutionId (InstanceActor static-write path)
→ AlarmActor.SpawnAlarmExecution → AlarmExecutionActor → ScriptRuntimeContext
All four computed trigger types participate. Expression triggers evaluate off
the dispatcher, so the writer of the newest value folded into the snapshot is
captured *with* the snapshot and echoed home on ExpressionEvalResult /
ExpressionEvalFailed — a change arriving mid-flight cannot mis-attribute the
raise.
Deliberately still roots (documented, not deferred): alarms fired by Data
Connection Layer values (external device data has no spawning execution — this
includes the device echo of a script write to a *data-sourced* attribute, so
only static writes cascade), and ScriptActor value-change/conditional/
expression/timer trigger runs (a timer tick has no spawner; a WhileTrue/interval
run has no single identifiable write).
Tests: new SiteRuntime.Tests/Actors/AlarmCascadeParentExecutionTests pins all
three hops — SetAttribute stamps the run's ExecutionId, InstanceActor publishes
it on the change (and publishes null when absent), and ValueMatch/HiLo/
Expression alarms parent the on-trigger run to the writer while a DCL-originated
change leaves it a root.
Docs: CLAUDE.md and Component-AuditLog.md corrected from "complete" to the true
behaviour; Component-SiteRuntime.md gains an "Audit correlation of an on-trigger
run" section with the hop table and the by-design root cases.
Two verified-absent parity gaps between the service layer and the CLI /
ManagementActor command surface, both left as follow-ups by the 2026-05-11
design plans.
(1) area move. AreaService.MoveAreaAsync had existed since the deployment
topology page shipped but was reachable only from the Blazor UI. Adds
MoveAreaCommand(AreaId, NewParentAreaId?) to Commons, a ManagementActor
dispatch arm delegating straight to AreaService.MoveAreaAsync (not-found /
self-parent / descendant-cycle / cross-site / name-collision all surface as
the standard curated ManagementCommandException failure response; the service
writes its own "Move" audit row), and the CLI verb `site area move --id
[--parent-id]`. Omitting --parent-id moves the area to the site root, matching
the command's nullable NewParentAreaId. The command carries the SAME any-of
[Designer, Deployer] gate as CreateArea/UpdateArea/DeleteArea (arch-review C6):
re-parenting is the same structural authoring act, exposed on the same two
surfaces. Placed under the existing `site area` group rather than a new
top-level `area` group, alongside its create/update/delete siblings.
(2) template folder verbs. The five folder management commands have been
handled by ManagementActor since the folder-hierarchy plan, but the promised
CLI surface was never written. Adds `template folder
list|create|rename|move|reorder|delete` mapping 1:1 onto ListTemplateFolders /
CreateTemplateFolder / RenameTemplateFolder / MoveTemplateFolder /
ReorderTemplateFolder / DeleteTemplateFolder. --parent-id is omitted to target
the tree root; --direction takes the lowercase literals up/down, validated at
parse time by AcceptOnlyFromAmong (same case-sensitive contract as the audit
--channel/--kind/--status options).
Follow-on updates: the frozen authorization matrix gains its MoveArea entry
(reflection-driven, so a missing entry would have failed CI); CommandTreeTests
pins both new verb sets plus the omit-parent-id-means-root parse behaviour and
registry round-trips; ManagementActorTests covers the MoveArea role gate and
the delegate-to-service success/root/cycle/not-found paths; the CLI README and
Component-ManagementService.md document the new surface (the latter also gained
the previously-undocumented ReorderTemplateFolder); both plan docs' follow-up
lines are marked done.
Phase 4 of the ClusterClient -> gRPC migration deleted the Akka transports
but left the naming behind: `ClusterClientSiteAuditClient` was transport-
agnostic and worked unchanged, so it survived the deletion under a name
that now describes a transport the repo no longer has. Same for a scatter
of doc-comments still framing gRPC as "the new transport" beside an Akka
one that is gone.
Renames it to `SiteCommunicationAuditClient` (and its test file) and
rewrites the stale comments to describe the single transport that exists.
Also tightens CLAUDE.md: drops the self-describing directory listing and
the 27-component enumeration in favour of the non-obvious parts only.
Behaviour-neutral: names and prose only. Recorded as the Phase 4
follow-up in docs/plans/2026-07-22-clusterclient-to-grpc-plan.md.
'Pattern 4: Integration Routing' — RouteIntegrationCallAsync →
SiteEnvelope(IntegrationCallRequest) → SiteCommunicationActor integration
handler — was plumbed end to end but connected at neither end: no
producer (zero callers) and no handler (AkkaHostedService never
registered LocalHandlerType.Integration). It was an early scaffold the
architecture routed around — the brokered External→Central→Site→Central
round-trip is served by the Inbound API's routed-site-script path (the
RouteTo* verbs, driven from CommunicationServiceInstanceRouter), which is
live, tested, and shares IntegrationTimeout.
Decision (#32): delete. Removed the IntegrationCall{Request,Response}
messages, RouteIntegrationCallAsync, the SiteCommunicationActor receive
block + _integrationHandler field + LocalHandlerType.Integration, and the
four tests that covered them (2 actor, 2 message-contract, 1 dispatcher-
reject, 1 mapper-reject). KEPT IntegrationTimeout — it is the live
timeout for the RouteTo* verbs. Updated the exclusion-narrative comments
(proto/mapper/dispatcher), design §4, the components doc timeout table,
and marked the known-issue RESOLVED.
Full solution build clean (0/0); Communication 634 + Host 421 green.
Net -172/+20 across 14 files. Not in the gRPC proto (was deliberately
excluded there), so no wire-format change.
Central and each site are SEPARATE Akka clusters, so central cannot act on a
site's membership -- it asks. New TriggerSiteFailover/SiteFailoverAck contract
travels the existing ClusterClient command/control channel (mirroring the
RetryParkedOperation relay); the site's own SiteCommunicationActor performs the
graceful Leave and acks the outcome.
- ClusterFailoverCoordinator moved out of Host into Communication/ClusterState,
beside ActiveNodeEvaluator. Both paths now share ONE oldest-Up implementation;
SiteCommunicationActor cannot reference Host, and the two definitions must not
drift or the node asked to leave stops being the singleton host.
- Site scope is the SITE-SPECIFIC role (site-{SiteId}), not the base Site role --
site singletons are placed on the former, so the base role would move the wrong
node. Pinned by a unit test asserting the role string and by a real-cluster test.
- Site-side guards: refuses a command addressed to another site (a misroute must
never fail over a site the operator did not select), refuses when there is no
peer, and reports a fault as an ack rather than throwing into supervision --
a restart there would drop central's Ask into a bare timeout and lose the reason.
- Ack is sent before the Leave takes effect so it still reaches central.
- UI: the same control now serves both scopes via a SiteId parameter. The site
confirmation deliberately does NOT claim the admin's page will disconnect --
it won't, and crying wolf there devalues the central warning that is real. A
site refusal and an unreachable site surface distinctly.
- Rolling upgrade: a site on an older binary has no handler, so the message
dead-letters and the Ask times out, reported as "site did not respond". That
is the honest outcome; documented on the contract.
Fallout fixed: HealthPageTests now renders the page inside
CascadingAuthenticationState with the real policy set and IAuthorizationService,
because the cards embed an AuthorizeView. That mirrors production, where the
layout supplies the cascading value.
Admin-triggered failover of the central pair. IManualFailoverService is declared in
CentralUI (plain strings, so that project stays Akka-free); AkkaManualFailoverService
implements it in the Host and is registered only in the Central branch.
- Leave, never Down: singletons hand over instead of being killed.
- Target = oldest Up member with the Central role, mirroring ActiveNodeEvaluator, so
the node acted on is exactly the one hosting the singletons (never the leader,
whose address-ordered definition diverges from singleton placement after a restart).
- Peer guard: returns null when fewer than 2 Up Central members — failing over a lone
node is an outage, not a failover.
- Audited BEFORE the Leave is issued via ICentralAuditWriter: the acting node can be
the one that goes away, and an audit written after could be lost to the shutdown it
describes. Best-effort — audit failure never blocks the failover.
New audit taxonomy: AuditChannel.Cluster + AuditKind.ManualFailover (operator-initiated
topology actions are not script trust-boundary crossings, but are exactly what an audit
log exists to attribute). Lock-in tests updated 5->6 channels, 16->17 kinds.
alog.md §4 updated per the lock-in tests' contract. Both tables were already stale --
the Channel row omitted SecuredWrite and the Kind table claimed 10 while the code had
16 -- so they are completed here, not merely appended to.
ManualFailoverTests: 3 real-cluster tests (oldest leaves + survivor takes over, peer
guard refuses with a positive still-running assert, dry-run probe does not perturb).
Tasks 8 and 9 of the LocalDb Phase 1 adoption plan.
Task 8 - LocalDbSyncAuthInterceptor. The replication library's LocalDbSyncService
verifies nothing; inbound auth is explicitly the host's job. Without this,
anything able to reach a site node's gRPC port could stream arbitrary rows into
the consolidated site database - including OperationTracking, which central
reconciles from.
Scoped strictly to /localdb_sync.v1.LocalDbSync/; SiteStream shares the same
AddGrpc pipeline and passes through untouched. Fail-closed: with no
LocalDb:Replication:ApiKey configured NO sync stream is accepted, authenticated
or not. That is deliberate - "no key" is the default every site node ships with,
so treating it as "no auth required" would expose the endpoint on precisely the
most common configuration. Comparison is FixedTimeEquals over UTF-8 bytes.
All four server handler shapes are gated, not just unary: the sync RPC is a
bidirectional stream, so gating only the unary path would leave the real endpoint
open while every unary test still passed. There is a test for that.
Deviation from the plan: it specified Grpc.Core.Testing for the fake
ServerCallContext. That type ships in the retired native Grpc.Core package and
does not exist on the grpc-dotnet stack this solution uses; a minimal
FakeServerCallContext in the test file was the better trade than adding a dead
dependency.
Task 9 - ISyncStatus onto the site health report as LocalDbReplicationConnected
and LocalDbOplogBacklog, via a delegate-seam hosted service following the
AddSiteEventLogHealthMetricsBridge precedent (HealthMonitoring takes no reference
on the replication library). Both are additive init properties, so the
Akka-remoted SiteHealthReport constructor signature is untouched.
Both fields are nullable and the distinction is load-bearing:
- null = the reporter has not run / replication is not wired ("no data");
- false/0 = a real reading. On a node with no peer that IS the healthy
default-OFF state, not an outage.
OplogBacklog is passed through nullable end-to-end because ISyncStatus returns
null when the poll fails - flattening it to 0 would report a replication pair
that cannot read its own oplog as perfectly healthy. The collector stores both
values as one tuple and CollectReport reads it once, so a torn read cannot pair a
fresh Connected with a stale backlog.
Verified: build 0 warnings; Host 307/307 (8 interceptor + 3 health tests new),
HealthMonitoring 97/97, Commons 684/684.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Tasks 2 + 5a-writer + 5b of the LocalDb Phase 1 plan, landed together because
they are one indivisible change: the schema, the writer that fills it, and every
consumer that assumed the old id semantics.
WHY the id changes. Site pairs will replicate site_events with last-writer-wins on
the primary key. With INTEGER PRIMARY KEY AUTOINCREMENT both nodes independently
mint 1, 2, 3... for unrelated events, so sync would treat them as the same row and
silently overwrite. A GUID makes the event log a pure union across the pair.
Task 2 - schema extracted so the Host's AddZbLocalDb onReady can create the tables
before RegisterReplicated installs capture triggers (pre-registration rows are
never captured):
- new OperationTrackingSchema.Apply / SiteEventLogSchema.Apply, plain
Microsoft.Data.Sqlite, no LocalDb dependency
- both stores delegate their InitializeSchema to them (idempotent, so a
directly-constructed store still works)
- OperationTracking is unchanged - it already had a TEXT PK and replicates as-is
Task 5a - SiteEventLogger mints Guid.NewGuid("N") per event and inserts it.
Task 5b - three consumers assumed a monotonic integer id. All three move to
timestamp ordering; leaving any one behind would be a live bug:
- EventLogQueryService: "id > $afterId" would return an ARBITRARY subset of a
GUID-keyed table and SILENTLY DROP ROWS from page-through. Now a composite
(timestamp, id) keyset cursor with an opaque string token; timestamps are not
unique, so id is the tie-break that guarantees exactly-once paging.
- EventLogPurgeService: "ORDER BY id ASC LIMIT 1000" would delete a RANDOM batch
instead of the oldest. Now orders by timestamp.
- EventLogEntry.Id and both ContinuationTokens: long -> string.
WIRE COMPATIBILITY. Those DTOs cross the site<->central Akka boundary
(SiteCommunicationActor -> CommunicationService -> ManagementActor / CentralUI).
No rolling-upgrade shim is needed because both sides ship in the same deployable
and the rig redeploys as a unit. Checked: no Akka serializer binding pins these
types by name. A stale numeric token degrades to "start from the beginning"
(a visible repeat) rather than throwing or losing rows.
Tests: the two that encoded the old semantics were rewritten to guard the new
invariant rather than deleted - uniqueness instead of monotonicity, and
oldest-purged-first keyed on timestamp. That second test also exposed a latent
weakness: the bulk seed stamped every row with the same UtcNow, so "oldest" was
never actually well-defined; rows now get distinct increasing timestamps, kept
inside the retention window so the retention purge does not eat them first.
Verified:
dotnet build ZB.MOM.WW.ScadaBridge.slnx -> 0 Error(s), 0 Warning(s)
SiteEventLogging.Tests -> 70 passed (12 new schema tests, red-first)
CentralUI.Tests -> 925 passed
Commons.Tests -> 684 passed
SiteRuntime.Tests -> 529 passed, 1 pre-existing flaky failure
(InstanceActorChildAttributeRaceTests - passes 3/3 in
isolation with and without this change)
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Joseph Doherty