api

Documentation

Index

• Variables
• func GetThresholdQuantity(value ThresholdValue, capacity *resource.Quantity) *resource.Quantity
• type Signal
• type Threshold
• type ThresholdOperator
• type ThresholdValue

Variables

var OpForSignal = map[Signal]ThresholdOperator{
	SignalMemoryAvailable:            OpLessThan,
	SignalNodeFsAvailable:            OpLessThan,
	SignalNodeFsInodesFree:           OpLessThan,
	SignalImageFsAvailable:           OpLessThan,
	SignalImageFsInodesFree:          OpLessThan,
	SignalAllocatableMemoryAvailable: OpLessThan,
	SignalPIDAvailable:               OpLessThan,
}

OpForSignal maps Signals to ThresholdOperators. Today, the only supported operator is "LessThan". This may change in the future, for example if "consumed" (as opposed to "available") type signals are added. In both cases the directionality of the threshold is implicit to the signal type (for a given signal, the decision to evict will be made when crossing the threshold from either above or below, never both). There is thus no reason to expose the operator in the Kubelet's public API. Instead, we internally map signal types to operators.

Functions

func GetThresholdQuantity

func GetThresholdQuantity(value ThresholdValue, capacity *resource.Quantity) *resource.Quantity

GetThresholdQuantity returns the expected quantity value for a thresholdValue

Types

type Signal

type Signal string

Signal defines a signal that can trigger eviction of pods on a node.

const (
	// SignalMemoryAvailable is memory available (i.e. capacity - workingSet), in bytes.
	SignalMemoryAvailable Signal = "memory.available"
	// SignalNodeFsAvailable is amount of storage available on filesystem that kubelet uses for volumes, daemon logs, etc.
	SignalNodeFsAvailable Signal = "nodefs.available"
	// SignalNodeFsInodesFree is amount of inodes available on filesystem that kubelet uses for volumes, daemon logs, etc.
	SignalNodeFsInodesFree Signal = "nodefs.inodesFree"
	// SignalImageFsAvailable is amount of storage available on filesystem that container runtime uses for storing images and container writable layers.
	SignalImageFsAvailable Signal = "imagefs.available"
	// SignalImageFsInodesFree is amount of inodes available on filesystem that container runtime uses for storing images and container writable layers.
	SignalImageFsInodesFree Signal = "imagefs.inodesFree"
	// SignalAllocatableMemoryAvailable is amount of memory available for pod allocation (i.e. allocatable - workingSet (of pods), in bytes.
	SignalAllocatableMemoryAvailable Signal = "allocatableMemory.available"
	// SignalPIDAvailable is amount of PID available for pod allocation
	SignalPIDAvailable Signal = "pid.available"
)

type Threshold

type Threshold struct {
	// Signal defines the entity that was measured.
	Signal Signal
	// Operator represents a relationship of a signal to a value.
	Operator ThresholdOperator
	// Value is the threshold the resource is evaluated against.
	Value ThresholdValue
	// GracePeriod represents the amount of time that a threshold must be met before eviction is triggered.
	GracePeriod time.Duration
	// MinReclaim represents the minimum amount of resource to reclaim if the threshold is met.
	MinReclaim *ThresholdValue
}

Threshold defines a metric for when eviction should occur.

type ThresholdOperator

type ThresholdOperator string

ThresholdOperator is the operator used to express a Threshold.

const (
	// OpLessThan is the operator that expresses a less than operator.
	OpLessThan ThresholdOperator = "LessThan"
)

type ThresholdValue

type ThresholdValue struct {

	// Quantity is a quantity associated with the signal that is evaluated against the specified operator.
	Quantity *resource.Quantity
	// Percentage represents the usage percentage over the total resource that is evaluated against the specified operator.
	Percentage float32
}

ThresholdValue is a value holder that abstracts literal versus percentage based quantity