--- title: Querying Metrics from Prometheus description: This task shows you how to query for Istio Metrics using Prometheus. weight: 30 --- This task shows you how to query for Istio Metrics using Prometheus. As part of this task, you will use the web-based interface for querying metric values. The [Bookinfo](/docs/guides/bookinfo/) sample application is used as the example application throughout this task. ## Before you begin [Install Istio](/docs/setup/) in your cluster and deploy an application. ## Querying Istio Metrics 1. Verify that the prometheus service is running in your cluster (since 0.8 the prometheus setup is included in istio-demo.yaml and istio-demo-auth.yaml by default) In Kubernetes environments, execute the following command: ```command $ kubectl -n istio-system get svc prometheus NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE prometheus 10.59.241.54 9090/TCP 2m ``` 1. Send traffic to the mesh. For the Bookinfo sample, visit `http://$GATEWAY_URL/productpage` in your web browser or issue the following command: ```command $ curl http://$GATEWAY_URL/productpage ``` > `$GATEWAY_URL` is the value set in the [Bookinfo](/docs/guides/bookinfo/) guide. 1. Open the Prometheus UI. In Kubernetes environments, execute the following command: ```command $ kubectl -n istio-system port-forward $(kubectl -n istio-system get pod -l app=prometheus -o jsonpath='{.items[0].metadata.name}') 9090:9090 & ``` Visit [http://localhost:9090/graph](http://localhost:9090/graph) in your web browser. 1. Execute a Prometheus query. In the "Expression" input box at the top of the web page, enter the text: `istio_request_count`. Then, click the **Execute** button. The results will be similar to: {{< image width="100%" ratio="39.36%" link="../img/prometheus_query_result.png" caption="Prometheus Query Result" >}} Other queries to try: - Total count of all requests to `productpage` service: ``` istio_request_count{destination_service="productpage.default.svc.cluster.local"} ``` - Total count of all requests to `v3` of the `reviews` service: ``` istio_request_count{destination_service="reviews.default.svc.cluster.local", destination_version="v3"} ``` This query returns the current total count of all requests to the v3 of the reviews service. - Rate of requests over the past 5 minutes to all `productpage` services: ``` rate(istio_request_count{destination_service=~"productpage.*", response_code="200"}[5m]) ``` ### About the Prometheus add-on Mixer comes with a built-in [Prometheus](https://prometheus.io) adapter that exposes an endpoint serving generated metric values. The Prometheus add-on is a Prometheus server that comes preconfigured to scrape Mixer endpoints to collect the exposed metrics. It provides a mechanism for persistent storage and querying of Istio metrics. The configured Prometheus add-on scrapes three endpoints: 1. *istio-mesh* (`istio-mixer.istio-system:42422`): all Mixer-generated mesh metrics. 1. *mixer* (`istio-mixer.istio-system:9093`): all Mixer-specific metrics. Used to monitor Mixer itself. 1. *envoy* (`istio-mixer.istio-system:9102`): raw stats generated by Envoy (and translated from statsd to prometheus). For more on querying Prometheus, please read their [querying docs](https://prometheus.io/docs/querying/basics/). ## Cleanup - Remove any `kubectl port-forward` processes that may still be running: ```command $ killall kubectl ``` - If you are not planning to explore any follow-on tasks, refer to the [Bookinfo cleanup](/docs/guides/bookinfo/#cleanup) instructions to shutdown the application. ## What's next - Refer to the [In-Depth Telemetry](/docs/guides/telemetry/) guide.