Chapter 34. AWS XRay Component

Include the camel-aws-xray component in your POM, along with any specific dependencies associated with the AWS XRay Tracer.

To explicitly configure AWS XRay support, instantiate the XRayTracer and initialize the camel context. You can optionally specify a Tracer, or alternatively it can be implicitly discovered using the Registry or ServiceLoader.

XRayTracer xrayTracer = new XRayTracer();
// By default it uses a NoopTracingStrategy, but you can override it with a specific InterceptStrategy implementation.
xrayTracer.setTracingStrategy(...);
// And then initialize the context
xrayTracer.init(camelContext);

XRayTracer xrayTracer = new XRayTracer();
// By default it uses a NoopTracingStrategy, but you can override it with a specific InterceptStrategy implementation.
xrayTracer.setTracingStrategy(...);
// And then initialize the context
xrayTracer.init(camelContext);

To use XRayTracer in XML, all you need to do is to define the AWS XRay tracer bean. Camel will automatically discover and use it.

  <bean id="tracingStrategy" class="..."/>
  <bean id="aws-xray-tracer" class="org.apache.camel.component.aws.xray.XRayTracer" />
    <property name="tracer" ref="tracingStrategy"/>
  </bean>

  <bean id="tracingStrategy" class="..."/>
  <bean id="aws-xray-tracer" class="org.apache.camel.component.aws.xray.XRayTracer" />
    <property name="tracer" ref="tracingStrategy"/>
  </bean>

In case of the default NoopTracingStrategy only the creation and deletion of exchanges is tracked but not the invocation of certain beans or EIP patterns.

In order to track the execution of an exchange among multiple routes, on exchange creation a unique trace ID is generated and stored in the headers if no corresponding value was yet available. This trace ID is copied over to new exchanges in order to keep a consistent view of the processed exchange.

As AWS XRay traces work on a thread-local basis the current sub/segment should be copied over to the new thread and set as explained in in the AWS XRay documentation. The Camel AWS XRay component therefore provides an additional header field that the component will use in order to set the passed AWS XRay Entity to the new thread and thus keep the tracked data to the route rather than exposing a new segment which seems uncorrelated with any of the executed routes.

The component will use the following constants found in the headers of the exchange:

Note that the AWS XRay Entity (i.e., Segment and Subsegment) are not serializable and therefore should not get passed to other JVM processes.