org.axonframework.eventsourcing.eventstore

Class EmbeddedEventStore.Builder

java.lang.Object

org.axonframework.eventhandling.AbstractEventBus.Builder

org.axonframework.eventsourcing.eventstore.AbstractEventStore.Builder

org.axonframework.eventsourcing.eventstore.EmbeddedEventStore.Builder

Enclosing class:

EmbeddedEventStore

public static class EmbeddedEventStore.Builder
extends AbstractEventStore.Builder

Builder class to instantiate an EmbeddedEventStore.

The following configurable fields have defaults:

• The MessageMonitor is defaulted to a NoOpMessageMonitor.
• The SpanFactory is defaulted to a NoOpSpanFactory.
• The cachedEvents is defaulted to 10000.
• The fetchDelay is defaulted to 1000.
• The cleanupDelay is defaulted to 10000.
• The TimeUnit is defaulted to TimeUnit.MILLISECONDS.
• The ThreadFactory is defaulted to AxonThreadFactory with ThreadGroup EmbeddedEventStore.THREAD_GROUP.
• The optimizeEventConsumption is defaulted to true.

The EventStorageEngine is a hard requirement and as such should be provided.

Field Summary

Fields inherited from class org.axonframework.eventsourcing.eventstore.AbstractEventStore.Builder

storageEngine

Constructor Summary

Constructors

Constructor and Description
Builder()

Method Summary

Modifier and Type	Method and Description
EmbeddedEventStore	build() Initializes a EmbeddedEventStore as specified through this Builder.
EmbeddedEventStore.Builder	cachedEvents(int cachedEvents) Sets the maximum number of events in the cache that is shared between the streams of tracking event processors.
EmbeddedEventStore.Builder	cleanupDelay(long cleanupDelay) Sets the delay between two clean ups of lagging event processors.
EmbeddedEventStore.Builder	fetchDelay(long fetchDelay) Sets the time to wait before fetching new events from the backing storage engine while tracking after a previous stream was fetched and read.
EmbeddedEventStore.Builder	messageMonitor(MessageMonitor<? super EventMessage<?>> messageMonitor) Sets the MessageMonitor to monitor ingested EventMessages.
EmbeddedEventStore.Builder	optimizeEventConsumption(boolean optimizeEventConsumption) Sets whether event consumption should be optimized between Event Stream.
EmbeddedEventStore.Builder	spanFactory(SpanFactory spanFactory) Sets the SpanFactory implementation to use for providing tracing capabilities.
EmbeddedEventStore.Builder	storageEngine(EventStorageEngine storageEngine) Sets the EventStorageEngine used to store and load events.
EmbeddedEventStore.Builder	threadFactory(ThreadFactory threadFactory) Sets the ThreadFactory used to create threads for consuming, producing and cleaning up.
EmbeddedEventStore.Builder	timeUnit(TimeUnit timeUnit) Sets the TimeUnit for the fetchDelay and cleanupDelay.
protected void	validate() Validates whether the fields contained in this Builder are set accordingly.

Methods inherited from class java.lang.Object

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

Constructor Detail

Builder

public Builder()

Method Detail

storageEngine

public EmbeddedEventStore.Builder storageEngine(EventStorageEngine storageEngine)

Description copied from class: AbstractEventStore.Builder

Sets the EventStorageEngine used to store and load events.

Overrides:

storageEngine in class AbstractEventStore.Builder

Parameters:

storageEngine - the EventStorageEngine used to store and load events

Returns:

the current Builder instance, for fluent interfacing

messageMonitor

public EmbeddedEventStore.Builder messageMonitor(@Nonnull
                                                 MessageMonitor<? super EventMessage<?>> messageMonitor)

Description copied from class: AbstractEventBus.Builder

Sets the MessageMonitor to monitor ingested EventMessages. Defaults to a NoOpMessageMonitor.

Overrides:

messageMonitor in class AbstractEventStore.Builder

Parameters:

messageMonitor - a MessageMonitor to monitor ingested EventMessages

Returns:

the current Builder instance, for fluent interfacing

spanFactory

public EmbeddedEventStore.Builder spanFactory(@Nonnull
                                              SpanFactory spanFactory)

Description copied from class: AbstractEventBus.Builder

Sets the SpanFactory implementation to use for providing tracing capabilities. Defaults to a NoOpSpanFactory by default, which provides no tracing capabilities.

Overrides:

spanFactory in class AbstractEventBus.Builder

Parameters:

spanFactory - The SpanFactory implementation

Returns:

The current Builder instance, for fluent interfacing.

cachedEvents

public EmbeddedEventStore.Builder cachedEvents(int cachedEvents)

Sets the maximum number of events in the cache that is shared between the streams of tracking event processors. Defaults to 10000.

Parameters:

cachedEvents - an int specifying the maximum number of events in the cache that is shared between the streams of tracking event processors

Returns:

the current Builder instance, for fluent interfacing

fetchDelay

public EmbeddedEventStore.Builder fetchDelay(long fetchDelay)

Sets the time to wait before fetching new events from the backing storage engine while tracking after a previous stream was fetched and read. Note that this only applies to situations in which no events from the current application have meanwhile been committed. If the current application commits events then those events are fetched without delay.

Defaults to 1000. Together with the timeUnit, this will define the exact fetch delay.

Parameters:

fetchDelay - a long specifying the time to wait before fetching new events from the backing storage engine while tracking after a previous stream was fetched and read

Returns:

the current Builder instance, for fluent interfacing

cleanupDelay

public EmbeddedEventStore.Builder cleanupDelay(long cleanupDelay)

Sets the delay between two clean ups of lagging event processors. An event processor is lagging behind and removed from the set of processors that track cached events if the oldest event in the cache is newer than the last processed event of the event processor. Once removed the processor will be independently fetching directly from the event storage engine until it has caught up again. Event processors will not notice this change during tracking (i.e. the stream is not closed when an event processor falls behind and is removed).

Defaults to 1000. Together with the timeUnit, this will define the exact clean up delay.

Parameters:

cleanupDelay - a long specifying the delay between two clean ups of lagging event processors

Returns:

the current Builder instance, for fluent interfacing

timeUnit

public EmbeddedEventStore.Builder timeUnit(TimeUnit timeUnit)

Sets the TimeUnit for the fetchDelay and cleanupDelay. Defaults to TimeUnit.MILLISECONDS.

Parameters:

timeUnit - the TimeUnit for the fetchDelay and cleanupDelay

Returns:

the current Builder instance, for fluent interfacing

threadFactory

public EmbeddedEventStore.Builder threadFactory(ThreadFactory threadFactory)

Sets the ThreadFactory used to create threads for consuming, producing and cleaning up. Defaults to a AxonThreadFactory with ThreadGroup EmbeddedEventStore.THREAD_GROUP.

Parameters:

threadFactory - a ThreadFactory used to create threads for consuming, producing and cleaning up

Returns:

the current Builder instance, for fluent interfacing

optimizeEventConsumption

public EmbeddedEventStore.Builder optimizeEventConsumption(boolean optimizeEventConsumption)

Sets whether event consumption should be optimized between Event Stream. If set to true, distinct Event Consumers will read events from the same stream as soon as they reach the head of the stream. If false, they will stay on a private stream. The latter means more database resources will be used, but no side threads are created to fill the consumer cache nor locking is done on consumer threads. This field can also be configured by providing a system property with key optimize-event-consumption. Defaults to true.

Parameters:

optimizeEventConsumption - a boolean defining whether to optimize event consumption of threads by introducing a Event Cache Production thread tailing the head of the stream for the consumers

Returns:

the current Builder instance, for fluent interfacing

build

public EmbeddedEventStore build()

Initializes a EmbeddedEventStore as specified through this Builder.

Returns:

a EmbeddedEventStore as specified through this Builder

validate

protected void validate()
                 throws AxonConfigurationException

Validates whether the fields contained in this Builder are set accordingly.

Overrides:

validate in class AbstractEventStore.Builder

Throws:

AxonConfigurationException - if one field is asserted to be incorrect according to the Builder's specifications