istio.io/content/docs/tasks/telemetry/querying-metrics.md

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---
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 <none> 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.