Jaeger is an open source distributed tracing system. You use Jaeger for monitoring and troubleshooting microservices-based distributed systems. Using Jaeger you can perform a trace, which follows the path of a request through various microservices that make up an application. Jaeger is installed by default as part of the Service Mesh.

This tutorial uses Service Mesh and the bookinfo tutorial to demonstrate how you can use Jeager to perform distributed tracing.

The Bookinfo example application allows you to test your Red Hat OpenShift Service Mesh 1.0.2 installation on OpenShift Container Platform.

Red Hat does not provide support for the Bookinfo application.

Generating traces and analyzing trace data

This tutorial uses Service Mesh and the Bookinfo tutorial to demonstrate how you can perform a trace using the Jaeger component of Red Hat OpenShift Service Mesh.

Prerequisites:
  • OpenShift Container Platform 4.1 or higher installed.

  • Red Hat OpenShift Service Mesh 1.0.2 installed.

  • Jaeger enabled during the installation.

  • Bookinfo example application installed.

Procedure
  1. After you have deployed the Bookinfo application you will need to generate calls to the Bookinfo application so that you have some trace data to analyze. Access http://<GATEWAY_URL>/productpage and refresh the page a few times to generate some trace data.

  2. The installation process creates a route to access the Jaeger console.

    1. In the OpenShift Container Platform console, navigate to NetworkingRoutes and search for the Jaeger route, which is the URL listed under Location.

    2. Use the CLI to query for details of the route:

      $ export JAEGER_URL=$(oc get route -n bookinfo jaeger-query -o jsonpath='{.spec.host}')
  3. Launch a browser and navigate to https://<JAEGER_URL>;.

  4. If necessary, log in using the same user name and password as you use to access the OpenShift Container Platform console.

  5. In the left pane of the Jaeger dashboard, from the Service menu, select "productpage" and click the Find Traces button at the bottom of the pane. A list of traces is displayed, as shown in the following image:

    ossm jaeger main screen
  6. Click one of the traces in the list to open a detailed view of that trace. If you click on the top (most recent) trace, you see the details that correspond to the latest refresh of the `/productpage.

    ossm jaeger spans

    The trace in the previous figure consists of a few nested spans, each corresponding to a Bookinfo Service call, all performed in response to a `/productpage request. Overall processing time was 2.62s, with the details Service taking 3.56ms, the reviews Service taking 2.6s, and the ratings Service taking 5.32ms. Each of the calls to remote Services is represented by a client-side and server-side span. For example, the details client-side span is labeled productpage details.myproject.svc.cluster.local:9080. The span nested underneath it, labeled details details.myproject.svc.cluster.local:9080, corresponds to the server-side processing of the request. The trace also shows calls to istio-policy, which reflect authorization checks made by Istio.