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.
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.
The daily site_events retention purge (and the storage-cap trim) is CDC-captured
on a replication-enabled site node exactly like any other write — correct by
design, since LocalDb Phase 2 deliberately has no purge-exemption path — so the
backlog jumps by the deleted batch size at purge time. LocalDbOplogBacklog /
localdb_oplog_depth spike, drain, and an operator watching the gauge with no
context reads it as a replication fault.
Documentation + one log line, no behaviour change:
- topology-guide.md gains "Reading the replication backlog — the daily
site_events purge burst": when it fires (PurgeInterval 24h, anchored to the
active node's PROCESS START, not a wall-clock hour, so it moves after every
failover), where it shows (replicated nodes only — not rig site-b/site-c),
the healthy signature (LocalDbReplicationConnected stays true, backlog
returns to ~0) and what a genuine fault looks like instead.
- Component-SiteEventLogging.md Storage records the same under retention/purge;
Component-HealthMonitoring.md gains the two previously-undocumented
LocalDbReplicationConnected / LocalDbOplogBacklog metric rows carrying the
caveat, with cross-references both ways.
- EventLogPurgeService emits one Information line naming the row count and the
expected transient backlog when a purge deleted rows on a replication-enabled
node, so the spike is correlatable in the log. Replication-awareness comes in
as a Host-supplied SiteEventLogReplicationCheck delegate, mirroring the
existing SiteEventLogActiveNodeCheck seam: SiteLocalDbSetup.ReplicationIsConfigured
goes internal so the PeerAddress-OR-ApiKey rule stays in one place and
SiteEventLogging never learns to read LocalDb config. Unregistered ⇒ no note,
matching the default that replication is opt-in and off.
Both delete paths carry the note (a cap trim is usually the larger burst); the
predicate is try/caught since a log-wording check must never break the purge.
Tests: 5 new EventLogPurgeServiceTests cases (replicated logs it, unreplicated
does not, zero-rows does not, cap purge logs it, throwing predicate still purges
and swallows) via a local capturing ILogger. SiteEventLogging 81/81 green,
Host 490/490 green, full solution build clean (0 warnings).
Remediation from the full per-module code review at 4307c381 (findings recorded
separately in code-reviews/).
Highs fixed:
- DeploymentManager-025/SiteRuntime-031: stop broadcasting notification lists + SMTP
configs (incl. credentials) to sites; site purges already-persisted rows on apply
(enforces the central-only delivery design; clears plaintext SMTP creds at rest).
- DataConnectionLayer-023: guard the native-alarm subscribe path against the
mid-flight-unsubscribe adapter-feed leak (mirrors the DCL-021 tag-path fix).
- SiteEventLogging-024: normalize From/To query bounds to UTC (the -016 fix the
audit trail claimed but never committed).
- KpiHistory-001: add an in-flight guard to the recorder sample tick.
- ScriptAnalysis-001: harden the trust analyzer's TPA-absent fallback (resolve
forbidden anchors in the minimal reference set; warn on degraded mode) — anchors
added to validation references only, never the compile gate.
(InboundAPI-026 left to the feat/ipsen-movein effort per owner decision.)
Medium/Low: DM-026 deterministic deploy-status tiebreaker; SR-027/028/029/030
native-alarm leak/phantom-active/delete-during-redeploy fixes; AL-013/014/016;
TE-024 (folder-mutation audit rows now persisted)/025; SF-025 gauge-provider
clear-on-stop; ESG-025/026; SEC-023/024/025; SCA-007/008/009; plus doc/test
accuracy COM-023/024, HOST-025/026, HM-024/025, NS-027/028.
Full-solution build 0 warnings; ~3560 tests across 18 touched suites green.
Bundle D code-review feedback on 0ae1a25 and e6f7a7f:
- Audit error rate (HealthMonitoring tile) was described as a combined
view of CentralAuditWriteFailures + AuditRedactionFailure (writer
health). Per alog.md §10.3 / §14.1 it is the operational error rate
of audited operations: % of central AuditLog rows with Status not
in (Success/Delivered/Enqueued) over a rolling 5-min window. Audit
writer issues surface separately via the dedicated metrics.
- Audit volume description gains the spec-mandated 'events/min, global
+ per-site sparkline' shape.
- CLI: scadalink audit was claiming all three subcommands need both
OperationalAudit and AuditExport. Per alog.md §11.2 / §15.1, read
(query, verify-chain) needs OperationalAudit; bulk export
additionally requires AuditExport. Restored the spec's split.
Organize documentation by moving requirements (HighLevelReqs, Component-*,
lmxproxy_protocol) to docs/requirements/ and test infrastructure docs to
docs/test_infra/. Updates all cross-references in README, CLAUDE.md,
infra/README, component docs, and 23 plan files.
Joseph Doherty