mesh-catalog/modules/mesh-self-check/README.md

mesh-self-check

Holds the seat mesh-self-check (novox/hq ADR 0564 §6): the mesh's self-check, moved out of the controller. Go, one binary (cmd/mesh-self-check), served by a runtime of its own on its own bus account (runs-as), so that its account alone writes its buckets.

What it does

Every five minutes (the first run a minute after it starts) it runs its registry of probes, each within thirty seconds. A probe is one live invariant of a design, with its assertion as the controller had it, reading its facts on the bus (the bus module's tools for the bus's own state). A probe whose facts have no home on the bus yet answers deferred, naming them: never a pass. A probe that cannot run is said in the verdict at once, and written as a finding of its own (probe.<id>.failed) when the next run cannot run it either.

What a probe finds is written as a finding, one key <scope>.<id>.<kind> per fault, only when what it says changes, and deleted when a run no longer sees it. The condition keeper (mesh-conditions) raises and clears conditions from them. A finding one look can be wrong about (a consumer behind after a burst) is written when two runs in a row see it.

Every run ends with the event checked, the body of the controller's doctor-heartbeat, which the watchman (S10) and mesh-watcher on another machine hear: a self-check that stops checking is said through a path that does not pass through it.

What it keeps

• mesh-self-check_findings: what it finds wrong now.
• mesh-self-check_verdict: the key last, the last run whole.
• mesh-self-check_verdicts: every run (each probe's findings at most twenty), kept a week by the bucket's age.

Its verbs and tools

• mesh-self-check.doctor: the last verdict; run=true runs now; probe=<id> one probe whole.
• mesh-self-check.probes: the registry, with what each deferred probe lacks.
• self_check_findings, self_check_verdicts: the reads of its buckets.