Icon Telemetry FAQ

Can telemetry be accessed through REST?

You can collect telemetry data about Istio using Prometheus. And then use Prometheus’s HTTP API to query that data.

How can I control the data being reported by the sidecar?

It’s sometimes useful to exclude access to specific URLs from being reported. For example, you might wish to exclude some health-checking URLs. You can skip telemetry reports specific to certain URLs by excluding them using a match clause of the telemetry configuration such as:

match: source.name != "health"
Can the Prometheus adapter be used in non-Kubernetes environments?

You can use docker-compose to install Prometheus, similar to when you install your application. Also, without the Kubernetes API server, components such as Mixer will need local configuration for rules/handlers/instances.

Does Istio support request tracing for vert.x event bus messages?

Istio does not currently provide support for pub/sub and event bus protocols. Any use of those technologies is best-effort and subject to breakage.

How to figure out what happened to a request in Istio?

You can enable tracing to figure out the flow of a request in Istio.

Additionally, you can use following commands to know more about the state of the mesh:

  • istioctl proxy-config: Retrieves proxy configuration for the specified pod from the endpoint proxy or Pilot when running in Kubernetes.

    # Retrieve all config for productpage-v1-bb8d5cbc7-k7qbm pod from the endpoint proxy
    $ istioctl proxy-config endpoint productpage-v1-bb8d5cbc7-k7qbm
    
    # Try the following to know more proxy-config command:
    $ istioctl proxy-config --help
  • kubectl get: Gets information about different resources in mesh and routing configuration.

    # List all virtual services
    $ istioctl get virtualservices
    
    # Try following to know more proxy-config command:
    $ istioctl proxy-config --help
  • Mixer AccessLogs: Mixer writes access logs that contain information about requests. You can get them as follows:

    # Fill <istio namespace> with the namespace of your istio mesh. Ex: istio-system
    $ TELEMETRY_POD=`kubectl get po -n <istio namespace> | grep istio-telemetry | awk '{print $1;}'`
    $ kubectl logs $TELEMETRY_POD -c mixer  -n istio-system  | grep accesslog
What generates the initial ZipKin HTTP headers?

The Istio sidecar proxy (Envoy) generates the first headers.

How can I prevent Istio from sending trace spans to ZipKin?

If you already have tracing enabled, you can disable it as follows:

# Fill <istio namespace> with the namespace of your istio mesh.Ex: istio-system
TRACING_POD=`kubectl get po -n <istio namespace> | grep istio-tracing | awk ‘{print $1}`
$ kubectl delete pod $TRACING_POD -n <istio namespace>
$ kubectl delete services tracing zipkin   -n <istio namespace>
# Remove reference of zipkin url from mixer deployment
$ kubectl -n istio-system edit deployment istio-telemetry
# Now, manually remove instances of trace_zipkin_url from the file and save it.

Then follow the steps of the cleanup section of the Distributed Tracing task.

If you don’t want tracing functionality at all, then disable tracing in istio-demo.yaml or istio-demo-auth.yaml or don’t enable it when installing Istio.

Can Istio send tracing information to an external ZipKin instance?

To do so, you must you use the fully qualified domain name of the Zipkin instance. For example: zipkin.mynamespace.svc.cluster.local.

Is it possible to send x-request-id back when using Istio with ZipKin?

Istio doesn’t know when you make outbound calls from your application for which original request it was for unless you copy the headers. If you copy the headers, you can include it in your response headers too.