Package fish.payara.microprofile.faulttolerance.policy

Class FaultTolerancePolicy

java.lang.Object

fish.payara.microprofile.faulttolerance.policy.FaultTolerancePolicy

All Implemented Interfaces:

Serializable

public final class FaultTolerancePolicy
extends Object
implements Serializable

The FaultTolerancePolicy describes the effective aggregated policies to use for a particular Method when adding fault tolerant behaviour to it. The policies are extracted from FT annotations and the FaultToleranceConfig. In contrast to the plain annotations the policies do consider configuration overrides and include validation of the effective values. The policy class also reduces the need to analyse FT annotations for each invocation and works as a consistent source of truth throughout the processing of FT behaviour that is convenient to pass around as a single immutable value.

Author:

Jan Bernitt

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
AsynchronousPolicy	asynchronous
BulkheadPolicy	bulkhead
CircuitBreakerPolicy	circuitBreaker
FallbackPolicy	fallback
boolean	isMetricsEnabled
boolean	isNonFallbackEnabled
boolean	isPresent
RetryPolicy	retry
TimeoutPolicy	timeout

Constructor Summary

Constructors

Constructor	Description
FaultTolerancePolicy(boolean isNonFallbackEnabled, boolean isMetricsEnabled, AsynchronousPolicy asynchronous, BulkheadPolicy bulkhead, CircuitBreakerPolicy circuitBreaker, FallbackPolicy fallback, RetryPolicy retry, TimeoutPolicy timeout)

Method Summary

Modifier and Type	Method	Description
static FaultTolerancePolicy	asAnnotated(Class<?> target, Method annotated)
static void	clean()	Removes all expired policies from the cache.
static void	clean(ClassLoader appClassLoader)	Removes all expired policies from the cache and all policies related to this classloader
static FaultTolerancePolicy	get(jakarta.interceptor.InvocationContext context, Supplier<FaultToleranceConfig> configSpplier)	Returns the FaultTolerancePolicy to use for the method invoked in the current context.
boolean	isAsynchronous()
boolean	isBulkheadPresent()
boolean	isCircuitBreakerPresent()
boolean	isFallbackPresent()
boolean	isRetryPresent()
boolean	isTimeoutPresent()
Object	proceed(jakarta.interceptor.InvocationContext context, Supplier<FaultToleranceMethodContext> ftmContextSupplier)	Wraps InvocationContext.proceed() with fault tolerance behaviour.

Methods inherited from class java.lang.Object

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

Field Detail

isPresent

public final boolean isPresent

isNonFallbackEnabled

public final boolean isNonFallbackEnabled

isMetricsEnabled

public final boolean isMetricsEnabled

asynchronous

public final AsynchronousPolicy asynchronous

bulkhead

public final BulkheadPolicy bulkhead

circuitBreaker

public final CircuitBreakerPolicy circuitBreaker

fallback

public final FallbackPolicy fallback

retry

public final RetryPolicy retry

timeout

public final TimeoutPolicy timeout

Constructor Detail

FaultTolerancePolicy

public FaultTolerancePolicy(boolean isNonFallbackEnabled,
                            boolean isMetricsEnabled,
                            AsynchronousPolicy asynchronous,
                            BulkheadPolicy bulkhead,
                            CircuitBreakerPolicy circuitBreaker,
                            FallbackPolicy fallback,
                            RetryPolicy retry,
                            TimeoutPolicy timeout)

Method Detail

clean

public static void clean()

Removes all expired policies from the cache.

clean

public static void clean(ClassLoader appClassLoader)

Removes all expired policies from the cache and all policies related to this classloader

asAnnotated

public static FaultTolerancePolicy asAnnotated(Class<?> target,
                                               Method annotated)

get

public static FaultTolerancePolicy get(jakarta.interceptor.InvocationContext context,
                                       Supplier<FaultToleranceConfig> configSpplier)
                                throws org.eclipse.microprofile.faulttolerance.exceptions.FaultToleranceDefinitionException

Returns the FaultTolerancePolicy to use for the method invoked in the current context.

Parameters:

context - current context

configSpplier - supplies the configuration (if needed, in case returned policy needs to be created with help of the FaultToleranceConfig)

Returns:

the policy to apply

Throws:

org.eclipse.microprofile.faulttolerance.exceptions.FaultToleranceDefinitionException - in case the effective policy contains illegal values

isAsynchronous

public boolean isAsynchronous()

isBulkheadPresent

public boolean isBulkheadPresent()

isCircuitBreakerPresent

public boolean isCircuitBreakerPresent()

isFallbackPresent

public boolean isFallbackPresent()

isRetryPresent

public boolean isRetryPresent()

isTimeoutPresent

public boolean isTimeoutPresent()

proceed

public Object proceed(jakarta.interceptor.InvocationContext context,
                      Supplier<FaultToleranceMethodContext> ftmContextSupplier)
               throws Exception

Wraps InvocationContext.proceed() with fault tolerance behaviour. Processing has 6 stages:

 1) Asynchronous
 2) Fallback
 3) Retry
 4) Circuit Breaker
 5) Timeout
 6) Bulkhead
 

The call chain goes from 1) down to 6) skipping stages that are not requested by this policy. Asynchronous execution branches to new threads in stage 1) and 3) each executed by the FaultToleranceService#runAsynchronous(CompletableFuture, Callable).

Parameters:

context - intercepted call context

ftmContextSupplier - the environment used to execute the FT behaviour

Returns:

the result of InvocationContext.proceed() after applying FT behaviour

Throws:

Exception - as thrown by the wrapped invocation or a FaultToleranceException