Notice:

• This scaler requires prerequisites. See the ‘Prerequisites’ section.
• This scaler can scale to 0 only when user defines at least one additional scaler which is not CPU or Memory (eg. Kafka + Memory, or Prometheus + Memory) and minReplicaCount is 0.
• This scaler only applies to ScaledObject, not to Scaling Jobs.

Prerequisites

KEDA uses standard cpu and memory metrics from the Kubernetes Metrics Server, which is not installed by default on certain Kubernetes deployments such as EKS on AWS. Additionally, the resources section of the relevant Kubernetes Pods must include at least one of requests or limits.

• The Kubernetes Metrics Server must be installed. Installation instructions vary based on your Kubernetes provider.
• The configuration for your Kubernetes Pods must include a resources section with specified requests (or limits). See Resource Management for Pods and Containers. If the resources section is empty (resources: {} or similar), KEDA checks if the defaultRequest (or default for limits) is set in LimitRange for the Container type in the same namespace. If defaultRequest (or default for limits) is missing too, the error missing request for {cpu/memory} occurs.

# a working example of resources with specified requests
spec:
  containers:
  - name: app
    image: images.my-company.example/app:v4
    resources:
      requests:
        memory: "128Mi"
        cpu: "500m"

Trigger Specification

This specification describes the memory trigger that scales based on memory metrics.

triggers:
- type: memory
  metricType: Utilization # Allowed types are 'Utilization' or 'AverageValue'
  metadata:
    type: Utilization # Deprecated in favor of trigger.metricType; allowed types are 'Utilization' or 'AverageValue'
    value: "60"
    containerName: "" # Optional. You can use this to target a specific container in a pod

Parameter list:

• type - Type of metric to use. Options are Utilization, or AverageValue.
• value - Value to trigger scaling actions for:
  • When using Utilization, the target value is the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
  • When using AverageValue, the target value is the target value of the average of the metric across all relevant pods (quantity).
• containerName - Name of the specific container to scale based on its memory, rather than the entire pod. Defaults to empty if not specified.

💡 NOTE: containerName parameter requires Kubernetes cluster version 1.20 or higher with HPAContainerMetrics feature enabled. Please see container resource metrics for more information.

💡 NOTE: The type parameter is deprecated in favor of the global metricType and will be removed in a future release. Users are advised to use metricType instead.

Example

The following example targets memory utilization of entire pod. If the pod has multiple containers, it will be sum of all the containers in it.

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: memory-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: my-deployment
  triggers:
  - type: memory
    metricType: Utilization # Allowed types are 'Utilization' or 'AverageValue'
    metadata:
      value: "50"

The following example targets memory utilization of a specific container (foo) in a pod.

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: memory-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: my-deployment
  triggers:
  - type: memory
    metricType: Utilization # Allowed types are 'Utilization' or 'AverageValue'
    metadata:
      value: "50"
      containerName: "foo"