Module io.helidon.faulttolerance

Package io.helidon.faulttolerance

Class FaultTolerance

java.lang.Object

io.helidon.faulttolerance.FaultTolerance

public final class FaultTolerance
extends Object

System wide fault tolerance configuration and access to a customized sequence of fault tolerance handlers.

Fault tolerance provides the following features:

• Async - invoke a blocking synchronous call asynchronously in an executor service
• Bulkhead - limit number of parallel requests to a resource
• CircuitBreaker - stop trying to request a failing resource until it becomes available
• Fallback - fall back to another supplier of result in case the usual one fails
• Retry - try to call a supplier again if invocation fails
• Timeout - time out a request if it takes too long

See Also:

• config(io.helidon.config.Config)
• scheduledExecutor(java.util.function.Supplier)
• executor()
• builder()

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FaultTolerance.Builder	A builder used for setting up a customized list of fault tolerance handlers.
static class	FaultTolerance.TypedBuilder<T>	A builder used for fault tolerance handlers that require a specific type to be used, such as Fallback.

Method Summary

Modifier and Type	Method	Description
static FaultTolerance.Builder	builder()	A builder to configure a customized sequence of fault tolerance handlers.
static void	config(Config config)	Configure Helidon wide defaults from a config instance.
static void	executor(Supplier<? extends ExecutorService> executor)	Configure Helidon wide executor service for Fault Tolerance.
static boolean	initialized()	Mostly used for testing.
static void	scheduledExecutor(Supplier<? extends ScheduledExecutorService> executor)	Configure Helidon wide scheduled executor service for Fault Tolerance.
static <T> FaultTolerance.TypedBuilder<T>	typedBuilder()	A typed builder to configure a customized sequence of fault tolerance handlers.

Methods inherited from class java.lang.Object

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

Method Details

config

public static void config(Config config)

Configure Helidon wide defaults from a config instance.

Parameters:

config - config to read fault tolerance configuration

executor

public static void executor(Supplier<? extends ExecutorService> executor)

Configure Helidon wide executor service for Fault Tolerance.

Parameters:

executor - executor service to use, such as for Async

scheduledExecutor

public static void scheduledExecutor(Supplier<? extends ScheduledExecutorService> executor)

Configure Helidon wide scheduled executor service for Fault Tolerance.

Parameters:

executor - scheduled executor service to use, such as for Retry scheduling

initialized

public static boolean initialized()

Mostly used for testing. This class is considered to be initialized if any of its (lazy valued) executors were returned.

Returns:

boolean indicating whether init took place

builder

public static FaultTolerance.Builder builder()

A builder to configure a customized sequence of fault tolerance handlers.

Returns:

a new builder

typedBuilder

public static <T> FaultTolerance.TypedBuilder<T> typedBuilder()

A typed builder to configure a customized sequence of fault tolerance handlers.

Type Parameters:

T - type of result

Returns:

a new builder