Module io.helidon.faulttolerance

Package io.helidon.faulttolerance

Class CircuitBreaker.Builder

java.lang.Object

io.helidon.faulttolerance.CircuitBreaker.Builder

All Implemented Interfaces:

Builder<CircuitBreaker>, Supplier<CircuitBreaker>

Enclosing interface:

CircuitBreaker

public static class CircuitBreaker.Builder
extends Object
implements Builder<CircuitBreaker>

Fluent API builder for CircuitBreaker.

Method Summary

Modifier and Type	Method	Description
CircuitBreaker.Builder	addApplyOn(Class<? extends Throwable> clazz)	Add a throwable to be considered a failure.
CircuitBreaker.Builder	addSkipOn(Class<? extends Throwable> clazz)	This throwable will not be considered failure.
CircuitBreaker.Builder	applyOn(Class<? extends Throwable>... classes)	These throwables will be considered failures, and all other will not.
CircuitBreaker	build()	Build the instance from this builder.
CircuitBreaker.Builder	cancelSource(boolean cancelSource)	Policy to cancel any source stage if the value return by FtHandler.invoke(java.util.function.Supplier<? extends java.util.concurrent.CompletionStage<T>>) is cancelled.
CircuitBreaker.Builder	config(Config config)	Load all properties for this circuit breaker from configuration.
CircuitBreaker.Builder	delay(Duration delay)	How long to wait before transitioning from open to half-open state.
CircuitBreaker.Builder	errorRatio(int ratio)	How many failures out of 100 will trigger the circuit to open.
CircuitBreaker.Builder	executor(ScheduledExecutorService scheduledExecutor)	Executor service to schedule future tasks.
CircuitBreaker.Builder	name(String name)	A name assigned for debugging, error reporting or configuration purposes.
CircuitBreaker.Builder	skipOn(Class<? extends Throwable>... classes)	These throwables will not be considered failures, all other will.
CircuitBreaker.Builder	successThreshold(int successThreshold)	How many successful calls will close a half-open circuit.
CircuitBreaker.Builder	volume(int volume)	Rolling window size used to calculate ratio of failed requests.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.helidon.common.Builder

get

Method Detail

build

public CircuitBreaker build()

Description copied from interface: Builder

Build the instance from this builder.

Specified by:

build in interface Builder<CircuitBreaker>

Returns:

instance of the built type

delay

public CircuitBreaker.Builder delay(Duration delay)

How long to wait before transitioning from open to half-open state.

Parameters:

delay - to wait

Returns:

updated builder instance

errorRatio

public CircuitBreaker.Builder errorRatio(int ratio)

How many failures out of 100 will trigger the circuit to open. This is adapted to the volume(int) used to handle the window of requests.

If errorRatio is 40, and volume is 10, 4 failed requests will open the circuit.

Parameters:

ratio - percent of failure that trigger the circuit to open

Returns:

updated builder instance

See Also:

volume(int)

successThreshold

public CircuitBreaker.Builder successThreshold(int successThreshold)

How many successful calls will close a half-open circuit. Nevertheless the first failed call will open the circuit again.

Parameters:

successThreshold - number of calls

Returns:

updated builder instance

volume

public CircuitBreaker.Builder volume(int volume)

Rolling window size used to calculate ratio of failed requests.

Parameters:

volume - how big a window is used to calculate error errorRatio

Returns:

updated builder instance

See Also:

errorRatio(int)

applyOn

@SafeVarargs
public final CircuitBreaker.Builder applyOn(Class<? extends Throwable>... classes)

These throwables will be considered failures, and all other will not.

Cannot be combined with skipOn.

Parameters:

classes - to consider failures to calculate failure ratio

Returns:

updated builder instance

addApplyOn

public CircuitBreaker.Builder addApplyOn(Class<? extends Throwable> clazz)

Add a throwable to be considered a failure.

Parameters:

clazz - to consider failure to calculate failure ratio

Returns:

updated builder instance

See Also:

applyOn

skipOn

@SafeVarargs
public final CircuitBreaker.Builder skipOn(Class<? extends Throwable>... classes)

These throwables will not be considered failures, all other will.

Cannot be combined with applyOn.

Parameters:

classes - to consider successful

Returns:

updated builder instance

addSkipOn

public CircuitBreaker.Builder addSkipOn(Class<? extends Throwable> clazz)

This throwable will not be considered failure.

Parameters:

clazz - to consider successful

Returns:

updated builder instance

executor

public CircuitBreaker.Builder executor(ScheduledExecutorService scheduledExecutor)

Executor service to schedule future tasks. By default uses an executor configured on FaultTolerance.scheduledExecutor(java.util.function.Supplier).

Parameters:

scheduledExecutor - executor to use

Returns:

updated builder instance

name

public CircuitBreaker.Builder name(String name)

A name assigned for debugging, error reporting or configuration purposes.

Parameters:

name - the name

Returns:

updated builder instance

cancelSource

public CircuitBreaker.Builder cancelSource(boolean cancelSource)

Policy to cancel any source stage if the value return by FtHandler.invoke(java.util.function.Supplier<? extends java.util.concurrent.CompletionStage<T>>) is cancelled. Default is true; mostly used by FT MP to change default.

Parameters:

cancelSource - cancel source policy

Returns:

updated builder instance

config

public CircuitBreaker.Builder config(Config config)

Load all properties for this circuit breaker from configuration.

Configuration

key	default value	description
delay	5 seconds	Delay to transition from open to half-open
name	CircuitBreaker-N	Name used for debugging
error-ratio	60	Failure percentage that will open the breaker
success-threshold	1	Number of successful calls will close a half-open breaker
volume	10	Rolling window size
cancel-source	true	Cancel task source if task is cancelled

Parameters:

config - the config node to use

Returns:

updated builder instance