Module io.helidon.faulttolerance

Package io.helidon.faulttolerance

Interface CircuitBreaker

All Superinterfaces:

FtHandler

public interface CircuitBreaker
extends FtHandler

CircuitBreaker protects a potentially failing endpoint from overloading and the application from spending resources on those endpoints.

In case too many errors are detected, the circuit opens and all new requests fail with a CircuitBreakerOpenException for a period of time. After this period, attempts are made to check if the service is up again - if so, the circuit closes and requests can process as usual again.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	CircuitBreaker.Builder	Fluent API builder for CircuitBreaker.
static enum	CircuitBreaker.State	A circuit breaker can be in any of 3 possible states as defined by this enum.

Method Summary

Modifier and Type	Method	Description
static CircuitBreaker.Builder	builder()	Builder to customize configuration of the breaker.
CircuitBreaker.State	state()	Current breaker state.
void	state(CircuitBreaker.State newState)	Set state of this circuit breaker.

Methods inherited from interface io.helidon.faulttolerance.FtHandler

invoke, invokeMulti, name

Method Details

builder

static CircuitBreaker.Builder builder()

Builder to customize configuration of the breaker.

Returns:

a new builder

state

CircuitBreaker.State state()

Current breaker state. As the state may change within nanoseconds, this is for information only.

Returns:

current breaker state

state

void state(CircuitBreaker.State newState)

Set state of this circuit breaker. Note that all usual processes to re-close or open the circuit are in progress.

• If set to CircuitBreaker.State.OPEN, a timer will set it to half open in a while
• If set to CircuitBreaker.State.HALF_OPEN, it may close after first successful request
• If set to CircuitBreaker.State.CLOSED, it may open again if requests fail

So a subsequent call to state() may yield a different state than configured here

Parameters:

newState - state to configure