CircuitBreaker

Builders specified for CircuitBreaker, using the Partially-Applied Type technique.

The initial State of the CircuitBreaker. While in this state the circuit breaker allows tasks to be executed.

Contract:

• Exceptions increment the failures counter
• Successes reset the failure count to zero
• When the failures counter reaches the maxFailures count, the breaker is tripped into the Open state

State of the CircuitBreaker in which the circuit breaker has already allowed a task to go through, as a reset attempt, in order to test the connection.

Contract:

• The first task when Open has expired is allowed through without failing fast, just before the circuit breaker is evolved into the HalfOpen state
• All tasks attempted in HalfOpen fail-fast with an exception just as in Open state
• If that task attempt succeeds, the breaker is reset back to the Closed state, with the resetTimeout and the failures count also reset to initial values
• If the first call fails, the breaker is tripped again into the Open state (the resetTimeout is multiplied by the exponential backoff factor)

State of the CircuitBreaker in which the circuit breaker rejects all tasks with an ExecutionRejectedException.

Contract:

• all tasks fail fast with ExecutionRejectedException
• after the configured resetTimeout, the circuit breaker enters a HalfOpen state, allowing one task to go through for testing the connection

An enumeration that models the internal state of CircuitBreaker, kept in an Atomic for synchronization.

The initial state when initializing a CircuitBreaker is Closed. The available states:

• Closed in case tasks are allowed to go through
• Open in case the circuit breaker is active and rejects incoming tasks
• HalfOpen in case a reset attempt was triggered and it is waiting for the result in order to evolve in Closed, or back to Open

Type-alias to document timestamps specified in milliseconds, as returned by Scheduler.clockRealTime.

Builders specified for CircuitBreaker, using the Partially-Applied Type technique.

Example:

 import scala.concurrent.duration._
 import cats.effect.{IO, Clock}
 implicit val clock: Clock[IO] = Clock.create[IO]

 val cb = CircuitBreaker[IO].of(
   maxFailures = 10,
   resetTimeout = 3.second,
   exponentialBackoffFactor = 2
 )

Safe builder.

Unsafe builder (that violates referential transparency).

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