Using Jaeger to trace requests in Managed Service for YDB

The Jaeger distributed tracing platform helps monitor request status in distributed microservice application systems.

In this article, you will learn how to install the Jaeger platform in a Managed Service for Kubernetes cluster and configure it to work with Yandex Managed Service for YDB:

1. Install and configure Jaeger.
2. Install a test application to create load on a Kubernetes cluster.
3. Test Jaeger by making a few test requests.

Getting startedGetting started

1. If you do not have the Yandex Cloud command line interface yet, install and initialize it.

   The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

2. Create security groups for the Managed Service for Kubernetes cluster and its node groups.

   Warning

   The configuration of security groups determines the performance and availability of the cluster and the services and applications running in it.

3. Create a Managed Service for Kubernetes cluster and a node group in any suitable configuration. When creating them, specify the security groups prepared in advance.

4. Install kubectl and configure it to work with the created cluster.

Install and configure JaegerInstall and configure Jaeger

1. Install Jaeger over YDB from the Yandex Cloud Marketplace application catalog. When installing the application, select the default namespace (default).

2. Make sure that all the Jaeger pods have changed their state to Running:

   kubectl get pods | grep jaeger
   

3. Retrieve the service name for jaeger-ydb-store-agent:

   kubectl get svc | grep ydb-store-agent
   

   Result:

   <jaeger-ydb-store-agent_application_name> ClusterIP 10.2.238.190 ...
   

Install a test applicationInstall a test application

To test Jaeger, use the HotROD application that simulates Kubernetes cluster load with several microservices.

1. Create a manifest called hotrod.yaml with the application description:

   ---
   apiVersion: v1
   kind: Pod
   metadata:
     name: hotrod
   spec:
     containers:
     - name: hotrod
       image: jaegertracing/example-hotrod:latest
       env:
       - name: JAEGER_AGENT_HOST
         value: "<jaeger-ydb-store-agent_application_name>.default.svc.cluster.local"
       - name: JAEGER_AGENT_PORT
         value: "6831"
       ports:
       - containerPort: 8080
       - containerPort: 8081
       - containerPort: 8082
       - containerPort: 8083
   

2. Create a pod with the hotrod application:

   kubectl apply -f hotrod.yaml
   

3. Make sure the hotrod pods have changed their status to Running:

   kubectl get pods | grep hotrod
   

Test JaegerTest Jaeger

1. Retrieve the service name for jaeger-ydb-store-query:

   kubectl get svc | grep jaeger-ydb-store-query
   

   Result:

   <jaeger-ydb-store-query_application_name>  LoadBalancer  10.2.222.155  130.133.51.247  16686:31189/TCP ...
   

2. Configure port forwarding for the jaeger-ydb-store-query service to redirect to the local machine:

   kubectl port-forward service/<jaeger-ydb-store-query_application_name> 16686:16686
   

3. In a different console window, configure port forwarding for the hotrod application to redirect to the local machine:

   kubectl port-forward hotrod 8080:8080
   

4. Open hotrod's URI in your browser and make a few test requests to Jaeger.

   Note

   If the resource is unavailable at the specified URL, make sure that the security groups for the Managed Service for Kubernetes cluster and its node groups are configured correctly. If any rule is missing, add it.

5. Open Jaeger's URI in your browser.

   Make sure that the test requests have been transmitted successfully and have been included in the trace.

Delete the resources you createdDelete the resources you created

Delete the resources you no longer need to avoid paying for them:

1. Delete the Managed Service for YDB database.
2. Delete the Managed Service for Kubernetes cluster.
3. If you reserved a public static IP address for the cluster, delete it.