+++
title = "Prometheus"
availability = "v1.0+"
maintainer = "Community"
description = "Scale applications based on Prometheus."
go_file = "prometheus"
+++

### Trigger Specification

This specification describes the `prometheus` trigger that scales based on a Prometheus.

```yaml
triggers:
- type: prometheus
  metadata:
    # Required
    serverAddress: http://<prometheus-host>:9090
    metricName: http_requests_total
    threshold: '100'
    query: sum(rate(http_requests_total{deployment="my-deployment"}[2m])) # Note: query must return a vector/scalar single element response
```

The `serverAddress` indicates where Prometheus is running which contains the configured metric defined in `metricName` or `query`. If using VictoriaMetrics cluster version, set full URL to Prometheus querying API, e.g. `http://<vmselect>:8481/select/0/prometheus`

### Authentication Parameters

Not supported yet.

### Example

```yaml
apiVersion: keda.k8s.io/v1alpha1
kind: ScaledObject
metadata:
  name: prometheus-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    deploymentName: my-deployment
  triggers:
  - type: prometheus
    metadata:
      serverAddress: http://<prometheus-host>:9090
      metricName: http_requests_total
      threshold: '100'
      query: sum(rate(http_requests_total{deployment="my-deployment"}[2m]))
```