The gateway publishes its live MXAccess session counts, and the dashboard
could not reach them. Four things stood between the data and the card, and
only the last one is cosmetic:
The active tier was probed only for instances declared HasActiveRole. A
standalone gateway has no active/standby role, so its active tier was never
requested at all. The tempting fix is to declare mxgw HasActiveRole, and it
is wrong: that flag also paints an Active/Standby badge, so it would buy the
data by asserting a role that does not exist. The probe is now unconditional
for any reachable instance while ObserveActive stays role-gated, separating
"what does this tier report" from "am I the active half".
The active probe's parsed body was then discarded - only ready.Report was
kept - so InstanceSnapshot gains ActiveReport. The two tiers stay separate
rather than merged, because a check name is only unique within a tier.
The card's one data-rendering path, ClusterDataLine, is located by the Akka
leader/activeNode keys and would ignore session data even once present. The
new row follows that helper's own precedent and locates the check by the data
it carries - the total/ready/faulted triple - not by name, requiring all three
so a future check publishing a lone "total" cannot be mistaken for it.
Rendered on the card FACE, not inside the collapsed check list: a count behind
a disclosure triangle is one nobody reads. Zero is shown rather than hidden,
since a gateway holding no sessions is the interesting case and suppressing it
would make the row appear only when the news is good.
Cost, stated plainly: every reachable instance now makes one extra HTTP
request per poll. The unreachable-instance skip is untouched, so the
worst-case sweep duration - which is set by timeouts, not by healthy
round-trips - is unchanged. Four cadence tests were counting raw requests as a
proxy for "instances polled"; they now count ready-tier probes, which is what
they always meant and is robust to tier changes.
The Wonder registry comment claiming the active tier ran an empty check set
was true when written and stopped being true when the gateway added the
check; it now warns against the HasActiveRole shortcut instead.
183 tests pass (177 + 6), including a positive control on the absence
assertion so "row not rendered" cannot pass vacuously.
Tasks 3.4-3.6 of the overview-dashboard plan.
Polling (3.4/3.5):
- OverviewPollerService: one timer at the fastest configured cadence, each
target polled when its own interval is due, fan-out per sweep, no retries
(the next tick is the retry, so damping stays the only place that decides
whether a failure is worth showing).
- OverviewSnapshotStore: atomic swap of a complete immutable graph plus a
change event. Pages read it and never probe — the cache-first requirement.
- LeaderResolver: per-group leader from akka-cluster data, with the
split-brain flag scoped to members that are actually answering, so an
ordinary failover is not misread as a disagreement.
UI (3.6): ThemeShell + StatusPill/TechCard composition against the mockup;
instance cards carry the status stripe (dashed for Unreachable), the check
detail list and the raw ready/active signal line.
Two defects found by verification rather than by review:
- The active tier answers with a status code and an EMPTY body, but the client
demanded parseable JSON on every probe — so a healthy pair rendered as
"role unknown" instead of Active/Standby. Split into ProbeAsync (ready tier,
body is the payload) and ProbeStatusAsync (active tier, code is the answer).
Caught by a live smoke run against two fake health endpoints; the poller
tests now serve an empty body so they hold the fix.
- SweepAsync published even when cancellation was already requested, leaving a
half-probed registry as the store's final state on shutdown. It now checks
the token itself rather than relying on the transport to throw.
Also: app.UseAntiforgery() is required despite the anonymous-by-design
pipeline — AddRazorComponents stamps antiforgery metadata unconditionally and
the endpoint middleware hard-fails without it (every page was 500). Chosen
over DisableAntiforgery() so a future form is protected by default.
147 tests, 0 warnings. Live-verified end to end against fake endpoints:
Up/Unreachable/Active/Standby, leader chip, cluster-data line, KPI counts.
Joseph Doherty