💡 NOTE: Take into account API Datadog endpoints rate limits when defining polling interval. For more detailed information about polling intervals check the Polling intervals and Datadog rate limiting section.

Trigger Specification

This specification describes the datadog trigger that scales based on a Datadog metric.

triggers:
- type: datadog
  metadata:
    query: "sum:trace.redis.command.hits{env:none,service:redis}.as_count()"
    queryValue: "7"
    type: "global"
    age: "120"

Parameter list:

• query - The Datadog query to run.
• queryValue - Value to reach to start scaling.
• type - Whether to start scaling based on the value or the average between pods. (Values: average, global, Default:average, Optional)
• age: The time window (in seconds) to retrieve metrics from Datadog. (Default: 90, Optional)

Authentication

Datadog requires both an API key and an APP key to retrieve metrics from your account.

You should use TriggerAuthentication CRD to configure the authentication:

Parameter list:

• apiKey - Datadog API key.
• appKey - Datadog APP key.
• datadogSite - Datadog site where to get the metrics from. This is commonly referred as DD_SITE in Datadog documentation. (Default: datadoghq.com, Optional)

Example

The example below uses the default KEDA polling interval (30 seconds). Take into account that API Datadog endpoints are rate limited and reducing the polling interval can accelerate reaching it.

apiVersion: v1
kind: Secret
metadata:
  name: datadog-secrets
  namespace: my-project
type: Opaque
data:
  apiKey: # Required: base64 encoded value of Datadog apiKey
  appKey: # Required: base64 encoded value of Datadog appKey
  datadogSite: # Optional: base64 encoded value of Datadog site
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: keda-trigger-auth-datadog-secret
  namespace: my-project
spec:
  secretTargetRef:
    # Required: API key for your Datadog account
  - parameter: apiKey
    name: datadog-secrets
    key: apiKey
    # Required: APP key for your Datadog account
  - parameter: appKey
    name: datadog-secrets
    key: appKey
    # Optional: Datadog site. Default: "datadoghq.com"
  - parameter: datadogSite
    name: datadog-secrets
    key: datadogSite
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: datadog-scaledobject
  namespace: my-project
spec:
  scaleTargetRef:
    name: worker
  triggers:
  - type: datadog
    metadata:
      # Required: datadog metric query
      query: "sum:trace.redis.command.hits{env:none,service:redis}.as_count()"
      # Required: according to the number of query result, to scale the TargetRef
      queryValue: "7"
      # Optional: (Global or Average). Whether the target value is global or average per pod. Default: Average
      type: "Global"
      # Optional: The time window (in seconds) to retrieve metrics from Datadog. Default: 90
      age: "120"
    authenticationRef:
      name: keda-trigger-auth-datadog-secret

Polling intervals and Datadog rate limiting

API Datadog endpoints are rate limited. Depending on the state of the ScaledObject there are two different parameters to control how often (per ScaledObject) we query Datadog for a metric.

When scaling from 0 to 1, the polling interval is controlled by KEDA, using the spec.pollingInterval parameter in the ScaledObject definition. For example, if this parameter is set to 60, KEDA will poll Datadog for a metric value every 60 seconds while the number of replicas is 0.

While scaling from 1 to N, on top of KEDA, the HPA will also poll regularly Datadog for metrics, based on the --horizontal-pod-autoscaler-sync-period parameter to the kube-controller-manager, which by default is 15 seconds. For example, if the kube-controller-manager was started with --horizontal-pod-autoscaler-sync-period=30, the HPA will poll Datadog for a metric value every 30 seconds while the number of replicas is between 1 and N.