scaledown

Documentation

Index

• type ActuationStatus
• type Actuator
• type Planner

Types

type ActuationStatus

type ActuationStatus interface {
	// DeletionsInProgress returns two lists of node names that are
	// currently undergoing deletion, for empty and non-empty (i.e. drained)
	// nodes separately.
	DeletionsInProgress() (empty, drained []string)
	// DeletionsCount returns total number of ongoing deletions in a given
	// node group.
	DeletionsCount(nodeGroupId string) int
	// RecentEvictions returns a list of pods that were recently removed by
	// the Actuator and hence are likely to get recreated elsewhere in the
	// cluster.
	RecentEvictions() (pods []*apiv1.Pod)
}

ActuationStatus is used for feeding Actuator status back into Planner TODO: Replace ActuationStatus with simple struct with getter methods.

type Actuator

type Actuator interface {
	// StartDeletion triggers a new deletion process. Nodes passed to this
	// function are not guaranteed to be deleted, it is possible for the
	// Actuator to ignore some of them e.g. if max configured level of
	// parallelism is reached.
	StartDeletion(empty, needDrain []*apiv1.Node) (status.ScaleDownResult, []*status.ScaleDownNode, errors.AutoscalerError)
	// CheckStatus returns an immutable snapshot of ongoing deletions.
	CheckStatus() ActuationStatus
	// ClearResultsNotNewerThan removes information about deletions finished
	// before or exactly at the provided timestamp.
	ClearResultsNotNewerThan(time.Time)
	// DeletionResults returns deletion results since the last ClearResultsNotNewerThan call
	// in a map form, along with the timestamp of last result.
	DeletionResults() (map[string]status.NodeDeleteResult, time.Time)
}

Actuator is responsible for making changes in the cluster: draining and deleting nodes.

type Planner

type Planner interface {
	// UpdateClusterState provides the Planner with information about the cluster.
	UpdateClusterState(podDestinations, scaleDownCandidates []*apiv1.Node, as ActuationStatus, currentTime time.Time) errors.AutoscalerError
	// CleanUpUnneededNodes resets internal state of the Planner.
	CleanUpUnneededNodes()
	// NodesToDelete returns a list of nodes that can be deleted right now,
	// according to the Planner.
	NodesToDelete(currentTime time.Time) (empty, needDrain []*apiv1.Node)
	// UnneededNodes returns a list of nodes that either can be deleted
	// right now or in a near future, assuming nothing will change in the
	// cluster.
	UnneededNodes() []*apiv1.Node
	// UnremovableNodes returns a list of nodes that cannot be removed.
	// TODO(x13n): Add a guarantee that each node is either unneeded or
	// unremovable. This is not guaranteed by the current implementation.
	UnremovableNodes() []*simulator.UnremovableNode
	// NodeUtilizationMap returns information about utilization of
	// individual cluster nodes.
	NodeUtilizationMap() map[string]utilization.Info
}

Planner is responsible for selecting nodes that should be removed.