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.
Joseph Doherty
da276ff15a