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MySQLAutoscaler

What is MySQLAutoscaler

MySQLAutoscaler is a Kubernetes Custom Resource Definitions (CRD). It provides a declarative configuration for autoscaling MySQL compute resources and storage of database components in a Kubernetes native way.

MySQLAutoscaler CRD Specifications

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

Here, some sample MySQLAutoscaler CROs for autoscaling different components of database is given below:

Sample MySQLAutoscaler for MySQL:

apiVersion: autoscaling.kubedb.com/v1alpha1
kind: MySQLAutoscaler
metadata:
  name: my-as
  namespace: demo
spec:
  databaseRef:
    name: sample-mysql
  compute:
    mysql:
      trigger: "On"
      podLifeTimeThreshold: 5m
      minAllowed:
        cpu: 250m
        memory: 350Mi
      maxAllowed:
        cpu: 1
        memory: 1Gi
      controlledResources: ["cpu", "memory"]
  storage:
    mysql:
      trigger: "On"
      usageThreshold: 60
      scalingThreshold: 50
      expansionMode: "Online"

Here, we are going to describe the various sections of a MySQLAutoscaler crd.

A MySQLAutoscaler object has the following fields in the spec section.

spec.databaseRef

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

• spec.databaseRef.name : specifies the name of the MySQL object.

spec.compute

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

• spec.compute.mysql indicates the desired compute autoscaling configuration for a MySQL standalone or cluster.

All of them 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.
• InMemoryScalingThreshold the percentage of the Memory that will be passed as inMemorySizeGB for inmemory database engine, which is only available for the percona variant of the mysql.

spec.storage

spec.storage specifies the autoscaling configuration for the storage resources of the database components. This field consists of the following sub-field:

• spec.storage.mysql indicates the desired storage autoscaling configuration for a MySQL standalone or cluster.

All of them has the following sub-fields:

• trigger indicates if storage autoscaling is enabled for this component of the database. If “On” then storage autoscaling is enabled. If “Off” then storage autoscaling is disabled.
• usageThreshold indicates usage percentage threshold, if the current storage usage exceeds then storage autoscaling will be triggered.
• scalingThreshold indicates the percentage of the current storage that will be scaled.
• expansionMode specifies the mode of volume expansion when storage autoscaler performs volume expansion OpsRequest. Default value is Online.