...

Example #6: Client and Server with asynchronous JAX-RS service (server-side)

...

In this example server-side implementation of the JAX-RS service is going to be executed asynchronously. It poses a challenge from the tracing prospective as request and response are processed in different threads (in general). At the moment, Apache CXF does not support the transparent tracing spans management (except for default use case) but provides the simple ways to do that (by letting to transfer spans from thread to thread). The client-side code stays unchanged.

@Produces( { MediaType.APPLICATION_JSON } )
@GET
public void getBooks(@Suspended final AsyncResponse response, @Context final TracerContext tracer) throws Exception {
    tracer.continueSpan(new Traceable<Future<Void>>() {
        public Future<Void> call(final TracerContext context) throws Exception {
            return executor.submit(
                tracer.wrap("Getting Book", new Traceable<Void>() {
                    public Void call(final TracerContext context) throws Exception {
                        // Simulating a processing delay of 50ms
                        Thread.sleep(50);
                            
                        response.resume(
                            Arrays.asList(
                                new Book("Apache CXF Web Service Development", "Naveen Balani, Rajeev Hathi")
                            )
                        );
                            
                        return null;
                    }
                })
            );
        }
    });
}

The actual invocation of the request by the client (with service name tracer-client) and consequent invocation of the service on the server side (service name tracer-server) is going to generate the following sample traces:

Example #7: Client and Server with asynchronous invocation (client-side)

In this example server-side implementation of the JAX-RS service is going to be the default one:

@Produces( { MediaType.APPLICATION_JSON } )
@GET
public Collection<Book> getBooks() {
    return Arrays.asList(
        new Book("Apache CXF Web Service Development", "Naveen Balani, Rajeev Hathi")
    );
}

While the JAX-RS client implementation is going to perform the asynchronous invocation:

final Future<Response> future = client
    .target("http://localhost:8282/books")
    .request()
    .accept(MediaType.APPLICATION_JSON)
    .async()
    .get();

In this respect, there is no difference from the caller prospective however a bit more work is going under the hood to transfer the active tracing span from JAX-RS client request filter to client response filter as in general those are executed in different threads (similarly to server-side asynchronous JAX-RS resource invocation). The actual invocation of the request by the client (with service name tracer-client) and consequent invocation of the service on the server side (service name tracer-server) is going to generate the following sample traces:

Image Added

Distributed Tracing with OpenZipkin Brave and JAX-WS support

...