Consecutive availability failures since the last success.
Consecutive failed half-open probes since the breaker last opened.
The upstream host the breaker state is scoped to.
Epoch milliseconds at which the breaker opened, or null while closed.
Whether the reserved half-open probe is currently in flight.
A frozen copy of one host-scoped CircuitState record, as exposed by snapshotTransportState. The
hostfield names the upstream the breaker state is scoped to; the remaining fields mirror the live record's values at snapshot time.