Quarkus - Using OpenTracing

This guide explains how your Quarkus application can utilize opentracing to provide distributed tracing for interactive web applications.

Prerequisites

To complete this guide, you need:

  • less than 15 minutes

  • an IDE

  • JDK 1.8+ installed with JAVA_HOME configured appropriately

  • Apache Maven 3.5.3+

  • Docker

Architecture

In this guide, we create a straightforward REST application to demonstrate distributed tracing.

Solution

We recommend that you follow the instructions in the next sections and create the application step by step. However, you can skip right to the completed example.

Clone the Git repository: git clone https://github.com/quarkusio/quarkus-quickstarts.git, or download an archive.

The solution is located in the using-opentracing directory.

Creating the Maven project

First, we need a new project. Create a new project with the following command:

mvn io.quarkus:quarkus-maven-plugin:0.19.1:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=using-opentracing \
    -DclassName="org.acme.opentracing.TracedResource" \
    -Dpath="/hello" \
    -Dextensions="opentracing"

This command generates the Maven project with a REST endpoint and imports the smallrye-opentracing extension, which includes the OpenTracing support and the default Jaeger tracer.

Examine the JAX-RS resource

Open the src/main/java/org/acme/opentracing/TracedResource.java file and see the following content:

package org.acme.opentracing;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/hello")
public class TracedResource {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "hello";
    }
}

Notice that there is no tracing specific code included in the application. By default, requests sent to this endpoint will be traced without any code changes being required. It is also possible to enhance the tracing information. For more information on this, please see the MicroProfile OpenTracing specification.

Create the configuration

There are two ways to configure the Jaeger tracer within the application.

The first approach is by providing the properties within the src/main/resources/application.properties file:

quarkus.jaeger.service-name=myservice
quarkus.jaeger.sampler-type=const
quarkus.jaeger.sampler-param=1
quarkus.jaeger.endpoint=http://localhost:14268/api/traces

The second approach is to supply the properties as environment variables. These can be specified as jvm.args as shown in the following section.

If the quarkus.jaeger.service-name property (or JAEGER_SERVICE_NAME environment variable) is not provided then a "no-op" tracer will be configured, resulting in no tracing data being reported to the backend.

Currently the tracer can only be configured to report spans directly to the collector via HTTP, using the quarkus.jaeger.endpoint property (or JAEGER_ENDPOINT environment variable). Support for using the Jaeger agent, via UDP, will be available in a future version.

Run the application

The first step is to start the tracing system to collect and display the captured traces:

docker run -e COLLECTOR_ZIPKIN_HTTP_PORT=9411 -p 5775:5775/udp -p 6831:6831/udp -p 6832:6832/udp -p 5778:5778 -p 16686:16686 -p 14268:14268 -p 9411:9411 jaegertracing/all-in-one:latest

Now we are ready to run our application. If using application.properties to configure the tracer:

./mvnw compile quarkus:dev

or if configuring the tracer via environment variables:

./mvnw compile quarkus:dev -Djvm.args="-DJAEGER_SERVICE_NAME=myservice -DJAEGER_SAMPLER_TYPE=const -DJAEGER_SAMPLER_PARAM=1 -DJAEGER_ENDPOINT=http://localhost:14268/api/traces"

Once both the application and tracing system are started, you can make a request to the provided endpoint:

$ curl http://localhost:8080/hello
hello

When the first request has been submitted, the Jaeger tracer within the app will be initialized:

2019-01-14 17:36:38,580 localhost using-opentracing-dev.jar[14190] INFO  [i.j.Configuration] (XNIO-1 task-1) Initialized tracer=JaegerTracer(version=Java-0.33.1, serviceName=myservice, reporter=RemoteReporter(sender=HttpSender(), closeEnqueueTimeout=1000), sampler=ConstSampler(decision=true, tags={sampler.type=const, sampler.param=true}), tags={hostname=localhost.localdomain, jaeger.version=Java-0.33.1, ip=127.0.0.1}, zipkinSharedRpcSpan=false, expandExceptionLogs=false, useTraceId128Bit=false)

Then visit the Jaeger UI to see the tracing information.

Hit CTRL+C to stop the application.