Consecutive availability failures since the last success.
Consecutive failed half-open probes since the breaker last opened; scales the next cooldown.
Epoch milliseconds at which the breaker opened, or null while closed.
Whether the reserved half-open probe is currently in flight.
The mutable breaker record for one owner-and-host scope.
One entry exists per
(state owner, upstream host)pair, tracking the consecutive availability-failure streak, when the breaker opened (epoch milliseconds,nullwhile closed), whether the single post-cooldown probe is currently reserved, and how many consecutive probes have failed