controller

Documentation

Index

• Constants
• type Controller
  • func New(topicInformer informersV1.TopicInformer, ...) Controller
• type Deployer
  • func NewDeployer(config *rest.Config, brokers []string) (Deployer, error)

Constants

const DefaultScalerInterval = 97 * time.Millisecond

DefaultScalerInterval controls how often to run the scaling strategy. 97ms is chosen to avoid accidental locksteps with other systems such as OS schedulers or garbage collection.

Types

type Controller

type Controller interface {
	// Run requests that this controller starts doing its job, until an empty struct is sent on the close channel.
	Run(closeCh <-chan struct{})
	// SetScalerInterval changes the interval at which the controller recomputes the required number of replicas for functions.
	// Should not be called once running.
	SetScalingInterval(interval time.Duration)
}

Controller deploys functions by monitoring input lag to registered functions. To do so, it periodically runs some scaling logic and keeps track of (un-)registered functions, topics and deployments.

func New

func New(topicInformer informersV1.TopicInformer,
	functionInformer informersV1.FunctionInformer,
	deploymentInformer informersV1Beta1.DeploymentInformer,
	deployer Deployer,
	auto autoscaler.AutoScaler,
	port int) Controller

New initialises a new function controller, adding event handlers to the provided informers.

type Deployer

type Deployer interface {
	// Deploy requests that a function be initially deployed on k8s.
	Deploy(function *v1.Function) error

	// Undeploy is called when a function is unregistered.
	Undeploy(function *v1.Function) error

	// Update is called when a function is updated. The desired number of replicas of the function is provided.
	Update(function *v1.Function, replicas int) error

	// Scale is used to vary the number of replicas dedicated to a function, including going to zero.
	Scale(function *v1.Function, replicas int) error
}

Deployer allows the realisation of a function on k8s and its subsequent scaling to accommodate more/less load.

func NewDeployer

func NewDeployer(config *rest.Config, brokers []string) (Deployer, error)