Package org.axonframework.messaging.tracing.annotation

Class TracingHandlerEnhancerDefinition

java.lang.Object

org.axonframework.messaging.tracing.annotation.TracingHandlerEnhancerDefinition

All Implemented Interfaces:

HandlerEnhancerDefinition

@Internal
public final class TracingHandlerEnhancerDefinition
extends Object
implements HandlerEnhancerDefinition

HandlerEnhancerDefinition that wraps annotated message handlers in a tracing span named after the handling method (for example "BookRoomHandler.handle(BookRoom)"). Message-type agnostic: every annotated handler kind receives the same enhancement -- the span lifecycle is driven entirely by MessageHandlingMember / ProcessingContext. Each wrapper preserves the original member's marker interface (command, event, or query handling member), so metamodel construction that classifies handlers by marker interface is unaffected by tracing.

Discovered via the standard META-INF/services HandlerEnhancerDefinition ServiceLoader entry shipped with axon-messaging, so no explicit registration is required. The configured SpanFactory is resolved from the ProcessingContext's ApplicationContext at handle time -- when no factory is registered, the wrapper is a pass-through.

@EventSourcingHandler suppression. Members carrying the EventSourcingHandler handler attribute are suppressed by default: they fire once per event during entity replay (a hot path) and would flood traces with one span per replayed event. Suppression is decided before any span name is built or the SpanFactory is resolved, so a suppressed invocation carries no tracing cost beyond a boolean check. Set MessagingTracingSettings.eventSourcingHandlersEnabled() to true to trace them anyway.

Since:

4.6.0

Author:

Mitchell Herrijgers, Mateusz Nowak

Constructor Summary

Constructors

Constructor	Description
TracingHandlerEnhancerDefinition()

Method Summary

Modifier and Type	Method	Description
<T> MessageHandlingMember<T>	wrapHandler(MessageHandlingMember<T> original)	Enhance the given original handler.

Methods inherited from class java.lang.Object

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

Constructor Details

TracingHandlerEnhancerDefinition

public TracingHandlerEnhancerDefinition()

Method Details

wrapHandler

public <T> MessageHandlingMember<T> wrapHandler(MessageHandlingMember<T> original)

Description copied from interface: HandlerEnhancerDefinition

Enhance the given original handler. Implementations may return the original message handler.

Specified by:

wrapHandler in interface HandlerEnhancerDefinition

Type Parameters:

T - The type of object that will perform the actual handling of the message

Parameters:

original - The original message handler

Returns:

The enhanced message handler