CheckExecutorWorker had no Oban `unique` constraint, so every insert path
created a fresh job row: self-scheduling, JobHealthCheckWorker, the check
form/API/GraphQL, and — the main amplifier — Monitoring.schedule_check/1
called unconditionally by snmp.ex discovery after create_check/1, which is
an upsert that returns {:ok, check} even when the check already exists.
Every SNMP discovery pass re-enqueued a job for every existing check, so
the check_executors queue grew to ~70k jobs for ~5.7k checks and stopped
draining.
Add `unique: [keys: [:check_id], states: [:available, :scheduled,
:retryable], period: :infinity]`. `:executing` is excluded so perform/1's
self-reschedule does not conflict with its own running job.
Also add the `checks` and `check_executors` queues to config/dev.exs —
they were missing from dev entirely (prod's runtime.exs already had them).
Graham McIntire
d9bf4f260b