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MemcachedAutoscaler

What is MemcachedAutoscaler

MemcachedAutoscaler is a Kubernetes Custom Resource Definitions (CRD). It provides a declarative configuration for autoscaling Memcached compute resources in a Kubernetes native way.

MemcachedAutoscaler CRD Specifications

Like any official Kubernetes resource, a MemcachedAutoscaler has TypeMeta, ObjectMeta, Spec and Status sections.

Here is a sample MemcachedAutoscaler CRO for autoscaling different components of database is given below. Sample MemcachedAutoscaler:

apiVersion: autoscaling.kubedb.com/v1alpha1
kind: MemcachedAutoscaler
metadata:
  name: mc-as
  namespace: demo
spec:
  databaseRef:
    name: mc1
  opsRequestOptions:
    timeout: 3m
    apply: IfReady
  compute:
    memcached:
      trigger: "On"
      podLifeTimeThreshold: 5m
      resourceDiffPercentage: 20
      minAllowed:
        cpu: 400m
        memory: 400Mi
      maxAllowed:
        cpu: 1
        memory: 1Gi
      controlledResources: ["cpu", "memory"]
      containerControlledValues: "RequestsAndLimits"

Here, we are going to describe the various sections of a MemcachedAutoscaler crd. A MemcachedAutoscaler object has the following fields in the spec section.

spec.databaseRef

spec.databaseRef is a required field that point to the Memcached object for which the autoscaling will be performed. This field consists of the following sub-field:

spec.opsRequestOptions

These are the options to pass in the internally created opsRequest CRO. opsRequestOptions has three fields. They have been described in details here.

spec.compute

spec.compute specifies the autoscaling configuration for to compute resources i.e. cpu and memory of the database components. This field consists of the following sub-field:

• spec.compute.memcached indicates the desired compute autoscaling

spec.compute.memcached has the following sub-fields:

• trigger indicates if compute autoscaling is enabled for this component of the database. If “On” then compute autoscaling is enabled. If “Off” then compute autoscaling is disabled.
• minAllowed specifies the minimal amount of resources that will be recommended, default is no minimum.
• maxAllowed specifies the maximum amount of resources that will be recommended, default is no maximum.
• controlledResources specifies which type of compute resources (cpu and memory) are allowed for autoscaling. Allowed values are “cpu” and “memory”.
• containerControlledValues specifies which resource values should be controlled. Allowed values are “RequestsAndLimits” and “RequestsOnly”.
• resourceDiffPercentage specifies the minimum resource difference between recommended value and the current value in percentage. If the difference percentage is greater than this value than autoscaling will be triggered.
• podLifeTimeThreshold specifies the minimum pod lifetime of at least one of the pods before triggering autoscaling.

Next Steps

• Learn about Memcached crd here.
• Deploy your first Memcached database with Memcached by following the guide here.