org.axonframework.eventhandling.async

Class AsynchronousCluster

java.lang.Object

org.axonframework.eventhandling.AbstractCluster

org.axonframework.eventhandling.async.AsynchronousCluster

All Implemented Interfaces:

Cluster

public class AsynchronousCluster
extends AbstractCluster

Cluster implementation that publishes events to the subscribed Event Listeners asynchronously from the publishing thread. This implementation can be configured to retry event when processing fails. Furthermore, a SequencingPolicy will tell the cluster which Events need to be processed sequentially, and which may be processed in parallel from others.

Since:

2.0

Author:

Allard Buijze

See Also:

SequencingPolicy, TransactionManager

Constructor Summary

Constructors

Constructor and Description
AsynchronousCluster(String identifier, Executor executor, SequencingPolicy<? super EventMessage<?>> sequencingPolicy) Creates an AsynchronousCluster implementation using the given executor and sequencingPolicy.
AsynchronousCluster(String identifier, Executor executor, TransactionManager transactionManager, SequencingPolicy<? super EventMessage<?>> sequencingPolicy) Creates an AsynchronousCluster implementation using the given executor, transactionManager and sequencingPolicy.
AsynchronousCluster(String identifier, Executor executor, TransactionManager transactionManager, SequencingPolicy<? super EventMessage<?>> sequencingPolicy, ErrorHandler errorHandler) Creates an AsynchronousCluster implementation using the given executor, transactionManager and sequencingPolicy.
AsynchronousCluster(String identifier, Executor executor, UnitOfWorkFactory unitOfWorkFactory, SequencingPolicy<? super EventMessage<?>> sequencingPolicy, ErrorHandler errorHandler) Creates an AsynchronousCluster implementation using the given executor, unitOfWorkFactory and sequencingPolicy.

Method Summary

Methods

Modifier and Type	Method and Description
protected EventProcessor	newProcessingScheduler(EventProcessor.ShutdownCallback shutDownCallback) Creates a new scheduler instance that schedules tasks on the executor service for the managed EventListener.
void	publish(EventMessage... events) Publishes the given Events to the members of this cluster.
protected void	schedule(EventMessage<?> task) Schedules this task for execution when all pre-conditions have been met.

Methods inherited from class org.axonframework.eventhandling.AbstractCluster

getMembers, getMetaData, getName, subscribe, unsubscribe

Methods inherited from class java.lang.Object

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

Constructor Detail

AsynchronousCluster

public AsynchronousCluster(String identifier,
                   Executor executor,
                   TransactionManager transactionManager,
                   SequencingPolicy<? super EventMessage<?>> sequencingPolicy)

Creates an AsynchronousCluster implementation using the given executor, transactionManager and sequencingPolicy. Failed events are retried if they are not explicitly non-transient with an interval of 2 seconds.

Parameters:

identifier - The unique identifier of this cluster

executor - The executor to process event batches with

transactionManager - The TransactionManager that manages transactions around event processing batches

sequencingPolicy - The policy indicating which events must be processed sequentially, and which may be executed in parallel.

AsynchronousCluster

public AsynchronousCluster(String identifier,
                   Executor executor,
                   SequencingPolicy<? super EventMessage<?>> sequencingPolicy)

Creates an AsynchronousCluster implementation using the given executor and sequencingPolicy. Each handler will receive each event once, ignoring exceptions they may throw. The Unit of Work in which Events are handled is not backed by any Transaction Manager.

Parameters:

identifier - The unique identifier of this cluster

executor - The executor to process event batches with

sequencingPolicy - The policy indicating which events must be processed sequentially, and which may be executed in parallel.

AsynchronousCluster

public AsynchronousCluster(String identifier,
                   Executor executor,
                   TransactionManager transactionManager,
                   SequencingPolicy<? super EventMessage<?>> sequencingPolicy,
                   ErrorHandler errorHandler)

Creates an AsynchronousCluster implementation using the given executor, transactionManager and sequencingPolicy. Failures are processed by the given errorHandler.

The Cluster is initialized with a DefaultUnitOfWorkFactory, using the given transactionManager to manage the backing transactions.

Parameters:

identifier - The unique identifier of this cluster

executor - The executor to process event batches with

transactionManager - The TransactionManager that manages transactions around event processing batches

sequencingPolicy - The policy indicating which events must be processed sequentially, and which may be executed in parallel.

errorHandler - The handler that handles error during event processing

AsynchronousCluster

public AsynchronousCluster(String identifier,
                   Executor executor,
                   UnitOfWorkFactory unitOfWorkFactory,
                   SequencingPolicy<? super EventMessage<?>> sequencingPolicy,
                   ErrorHandler errorHandler)

Creates an AsynchronousCluster implementation using the given executor, unitOfWorkFactory and sequencingPolicy. Failures are processed by the given errorHandler.

If transactions are required, the given unitOfWorkFactory should be configured to create Transaction backed Unit of Work instances.

Parameters:

identifier - The unique identifier of this cluster

executor - The executor to process event batches with

unitOfWorkFactory - The Unit of Work Factory Manager that manages Units of Work around event processing

sequencingPolicy - The policy indicating which events must be processed sequentially, and which may be executed in parallel.

errorHandler - The handler that handles error during event processing

Method Detail

publish

public void publish(EventMessage... events)

Description copied from interface: Cluster

Publishes the given Events to the members of this cluster.

Implementations may do this synchronously or asynchronously. Although EventListeners are discouraged to throw exceptions, it is possible that they are propagated through this method invocation. In that case, no guarantees can be given about the delivery of Events at all Cluster members.

Parameters:

events - The Events to publish in the cluster

schedule

protected void schedule(EventMessage<?> task)

Schedules this task for execution when all pre-conditions have been met.

Parameters:

task - The task to schedule for processing.

newProcessingScheduler

protected EventProcessor newProcessingScheduler(EventProcessor.ShutdownCallback shutDownCallback)

Creates a new scheduler instance that schedules tasks on the executor service for the managed EventListener.

Parameters:

shutDownCallback - The callback that needs to be notified when the scheduler stops processing.

Returns:

a new scheduler instance