Chapter 8. Tracing requests using Jaeger
Using Jaeger with OpenShift Serverless allows you to enable distributed tracing for your serverless applications on OpenShift Container Platform.
Distributed tracing records the path of a request through the various services that make up an application.
It is used to tie information about different units of work together, to understand a whole chain of events in a distributed transaction. The units of work might be executed in different processes or hosts.
Developers can visualize call flows in large architectures with distributed tracing. which is useful for understanding serialization, parallelism, and sources of latency.
8.1. Configuring Jaeger for use with OpenShift Serverless
To configure Jaeger for use with OpenShift Serverless, you will need:
- Cluster administrator permissions on an OpenShift Container Platform cluster.
- A current installation of OpenShift Serverless Operator and Knative Serving.
- A current installation of the Jaeger Operator.
Create and apply a Jaeger custom resource YAML file that contains the following sample YAML:
Jaeger custom resource YAML
apiVersion: jaegertracing.io/v1 kind: Jaeger metadata: name: jaeger namespace: default
Enable tracing for Knative Serving, by editing the
KnativeServingresource and adding a YAML configuration for tracing.
Tracing YAML example
apiVersion: operator.knative.dev/v1alpha1 kind: KnativeServing metadata: name: knative-serving namespace: knative-serving spec: config: tracing: sample-rate: "0.1" 1 backend: zipkin 2 zipkin-endpoint: http://jaeger-collector.default.svc.cluster.local:9411/api/v2/spans 3 debug: "false" 4
sample-ratedefines sampling probability. Using
sample-rate: "0.1"means that 1 in 10 traces will be sampled.
backendmust be set to
zipkin-endpointmust point to your
jaeger-collectorservice endpoint. To get this endpoint, substitute the namespace where the Jaeger custom resource is applied.
- Debugging should be set to
false. Enabling debug mode by setting
debug: "true"allows all spans to be sent to the server, bypassing sampling.
Access the Jaeger web console to see tracing data. You can access the Jaeger web console by using the
jaegerroute’s hostname by entering the following command:
$ oc get route jaeger
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD jaeger jaeger-default.apps.example.com jaeger-query <all> reencrypt None
- Open the endpoint address in your browser to view the console.