Package org.axonframework.messaging.core.retry

Class ExponentialBackOffRetryPolicy

java.lang.Object

org.axonframework.messaging.core.retry.ExponentialBackOffRetryPolicy

All Implemented Interfaces:

DescribableComponent, RetryPolicy

public class ExponentialBackOffRetryPolicy
extends Object
implements RetryPolicy

A RetryScheduler that uses a backoff strategy, doubling the retry delay after each attempt.

Since:

4.2

Author:

Bert Laverman, Allard Buijze

Nested Class Summary

Nested classes/interfaces inherited from interface org.axonframework.messaging.core.retry.RetryPolicy

RetryPolicy.Outcome

Constructor Summary

Constructors

Constructor	Description
ExponentialBackOffRetryPolicy(long initialWaitTime)	Initializes an exponential delay policy with given initialWaitTime in milliseconds.

Method Summary

Modifier and Type	Method	Description
RetryPolicy.Outcome	defineFor(Message message, Throwable failure, List<Class<? extends Throwable>[]> previousFailures)	Provides the outcome for the policy given the failed message that was dispatched and resulted in given failure.
void	describeTo(ComponentDescriptor descriptor)	Describe the properties of this DescribableComponent with the given descriptor.

Methods inherited from class java.lang.Object

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

Constructor Details

ExponentialBackOffRetryPolicy

public ExponentialBackOffRetryPolicy(long initialWaitTime)

Initializes an exponential delay policy with given initialWaitTime in milliseconds.

Parameters:

initialWaitTime - the wait time for the first retry

Method Details

defineFor

public RetryPolicy.Outcome defineFor(@Nonnull
 Message message,
 @Nonnull
 Throwable failure,
 @Nonnull
 List<Class<? extends Throwable>[]> previousFailures)

Description copied from interface: RetryPolicy

Provides the outcome for the policy given the failed message that was dispatched and resulted in given failure. The previousFailures represent a summary of previous failures that have occurred in previous attemps to send this message.

Specified by:

defineFor in interface RetryPolicy

Parameters:

message - The message that failed

failure - The exception that occurred while dispatching

previousFailures - a summary of all previous failures

Returns:

the outcome describing the expected rescheduling behavior

describeTo

public void describeTo(@Nonnull
 ComponentDescriptor descriptor)

Description copied from interface: DescribableComponent

Describe the properties of this DescribableComponent with the given descriptor.

Components should call the appropriate describeProperty methods on the descriptor to register their properties. The descriptor is responsible for determining how these properties are formatted and structured in the final output.

Best Practices: As a general rule, all relevant fields of a DescribableComponent implementation should be described in this method. However, developers have discretion to include only the fields that make sense in the context. Not every field may be meaningful for description purposes, especially internal implementation details. Furthermore, components might want to expose different information based on their current state. The final decision on what properties to include lies with the person implementing the describeTo method, who should focus on providing information that is useful for understanding the component's configuration and state.

Example implementation:

 public void describeTo(ComponentDescriptor descriptor) {
     descriptor.describeProperty("name", this.name);
     descriptor.describeProperty("enabled", this.enabled);
     descriptor.describeProperty("configuration", this.configuration); // A nested component
     descriptor.describeProperty("handlers", this.eventHandlers);      // A collection
 }
 

Specified by:

describeTo in interface DescribableComponent

Parameters:

descriptor - The component descriptor to describe this DescribableComponentn its properties in.