scheduler

Documentation

Index

• Constants
• Variables
• func EqualPriority(_ *api.Pod, podLister algorithm.PodLister, nodeLister algorithm.NodeLister) (schedulerapi.HostPriorityList, error)
• func NewGenericScheduler(predicates map[string]algorithm.FitPredicate, ...) algorithm.ScheduleAlgorithm
• func NewHTTPExtender(config *schedulerapi.ExtenderConfig, apiVersion string) (algorithm.SchedulerExtender, error)
• func PrioritizeNodes(pod *api.Pod, podLister algorithm.PodLister, ...) (schedulerapi.HostPriorityList, error)
• type Binder
• type Config
• type ExtendedPodLister
• type FailedPredicateMap
• type FakeModeler
  • func (f *FakeModeler) AssumePod(pod *api.Pod)
  • func (f *FakeModeler) ForgetPod(pod *api.Pod)
  • func (f *FakeModeler) ForgetPodByKey(key string)
  • func (a *FakeModeler) LockedAction(do func())
• type FitError
  • func (f *FitError) Error() string
• type HTTPExtender
  • func (h *HTTPExtender) Filter(pod *api.Pod, nodes *api.NodeList) (*api.NodeList, error)
  • func (h *HTTPExtender) Prioritize(pod *api.Pod, nodes *api.NodeList) (*schedulerapi.HostPriorityList, int, error)
• type Scheduler
  • func New(c *Config) *Scheduler
  • func (s *Scheduler) Run()
• type SimpleModeler
  • func NewSimpleModeler(queuedPods, scheduledPods ExtendedPodLister) *SimpleModeler
  • func (s *SimpleModeler) AssumePod(pod *api.Pod)
  • func (s *SimpleModeler) ForgetPod(pod *api.Pod)
  • func (s *SimpleModeler) ForgetPodByKey(key string)
  • func (a *SimpleModeler) LockedAction(do func())
  • func (s *SimpleModeler) PodLister() algorithm.PodLister
• type SystemModeler

Constants

const (
	DefaultExtenderTimeout = 5 * time.Second
)

Variables

var ErrNoNodesAvailable = fmt.Errorf("no nodes available to schedule pods")

Functions

func EqualPriority

func EqualPriority(_ *api.Pod, podLister algorithm.PodLister, nodeLister algorithm.NodeLister) (schedulerapi.HostPriorityList, error)

EqualPriority is a prioritizer function that gives an equal weight of one to all nodes

func NewGenericScheduler

func NewGenericScheduler(predicates map[string]algorithm.FitPredicate, prioritizers []algorithm.PriorityConfig, extenders []algorithm.SchedulerExtender, pods algorithm.PodLister, random *rand.Rand) algorithm.ScheduleAlgorithm

func NewHTTPExtender

func NewHTTPExtender(config *schedulerapi.ExtenderConfig, apiVersion string) (algorithm.SchedulerExtender, error)

func PrioritizeNodes

func PrioritizeNodes(pod *api.Pod, podLister algorithm.PodLister, priorityConfigs []algorithm.PriorityConfig, nodeLister algorithm.NodeLister, extenders []algorithm.SchedulerExtender) (schedulerapi.HostPriorityList, error)

Prioritizes the nodes by running the individual priority functions sequentially. Each priority function is expected to set a score of 0-10 0 is the lowest priority score (least preferred node) and 10 is the highest Each priority function can also have its own weight The node scores returned by the priority function are multiplied by the weights to get weighted scores All scores are finally combined (added) to get the total weighted scores of all nodes

Types

type Binder

type Binder interface {
	Bind(binding *api.Binding) error
}

Binder knows how to write a binding.

type Config

type Config struct {
	// It is expected that changes made via modeler will be observed
	// by NodeLister and Algorithm.
	Modeler    SystemModeler
	NodeLister algorithm.NodeLister
	Algorithm  algorithm.ScheduleAlgorithm
	Binder     Binder

	// Rate at which we can create pods
	// If this field is nil, we don't have any rate limit.
	BindPodsRateLimiter util.RateLimiter

	// NextPod should be a function that blocks until the next pod
	// is available. We don't use a channel for this, because scheduling
	// a pod may take some amount of time and we don't want pods to get
	// stale while they sit in a channel.
	NextPod func() *api.Pod

	// Error is called if there is an error. It is passed the pod in
	// question, and the error
	Error func(*api.Pod, error)

	// Recorder is the EventRecorder to use
	Recorder record.EventRecorder

	// Close this to shut down the scheduler.
	StopEverything chan struct{}
}

type ExtendedPodLister

type ExtendedPodLister interface {
	algorithm.PodLister
	Exists(pod *api.Pod) (bool, error)
}

ExtendedPodLister: SimpleModeler needs to be able to check for a pod's existence in addition to listing the pods.

type FailedPredicateMap

type FailedPredicateMap map[string]sets.String

type FakeModeler

type FakeModeler struct {
	AssumePodFunc      func(pod *api.Pod)
	ForgetPodFunc      func(pod *api.Pod)
	ForgetPodByKeyFunc func(key string)
	// contains filtered or unexported fields
}

FakeModeler implements the SystemModeler interface.

func (*FakeModeler) AssumePod

func (f *FakeModeler) AssumePod(pod *api.Pod)

AssumePod calls the function variable if it is not nil.

func (*FakeModeler) ForgetPod

func (f *FakeModeler) ForgetPod(pod *api.Pod)

ForgetPod calls the function variable if it is not nil.

func (*FakeModeler) ForgetPodByKey

func (f *FakeModeler) ForgetPodByKey(key string)

ForgetPodByKey calls the function variable if it is not nil.

func (*FakeModeler) LockedAction

func (a *FakeModeler) LockedAction(do func())

LockedAction serializes calls of whatever is passed as 'do'.

type FitError

type FitError struct {
	Pod              *api.Pod
	FailedPredicates FailedPredicateMap
}

func (*FitError) Error

func (f *FitError) Error() string

implementation of the error interface

type HTTPExtender

type HTTPExtender struct {
	// contains filtered or unexported fields
}

HTTPExtender implements the algorithm.SchedulerExtender interface.

func (*HTTPExtender) Filter

func (h *HTTPExtender) Filter(pod *api.Pod, nodes *api.NodeList) (*api.NodeList, error)

Filter based on extender implemented predicate functions. The filtered list is expected to be a subset of the supplied list.

func (*HTTPExtender) Prioritize

func (h *HTTPExtender) Prioritize(pod *api.Pod, nodes *api.NodeList) (*schedulerapi.HostPriorityList, int, error)

Prioritize based on extender implemented priority functions. Weight*priority is added up for each such priority function. The returned score is added to the score computed by Kubernetes scheduler. The total score is used to do the host selection.

type Scheduler

type Scheduler struct {
	// contains filtered or unexported fields
}

Scheduler watches for new unscheduled pods. It attempts to find nodes that they fit on and writes bindings back to the api server.

func New

func New(c *Config) *Scheduler

New returns a new scheduler.

func (*Scheduler) Run

func (s *Scheduler) Run()

Run begins watching and scheduling. It starts a goroutine and returns immediately.

type SimpleModeler

type SimpleModeler struct {
	// contains filtered or unexported fields
}

SimpleModeler implements the SystemModeler interface with a timed pod cache.

func NewSimpleModeler

func NewSimpleModeler(queuedPods, scheduledPods ExtendedPodLister) *SimpleModeler

NewSimpleModeler returns a new SimpleModeler.

queuedPods: a PodLister that will return pods that have not been scheduled yet.
scheduledPods: a PodLister that will return pods that we know for sure have been scheduled.

func (*SimpleModeler) AssumePod

func (s *SimpleModeler) AssumePod(pod *api.Pod)

func (*SimpleModeler) ForgetPod

func (s *SimpleModeler) ForgetPod(pod *api.Pod)

func (*SimpleModeler) ForgetPodByKey

func (s *SimpleModeler) ForgetPodByKey(key string)

func (*SimpleModeler) LockedAction

func (a *SimpleModeler) LockedAction(do func())

LockedAction serializes calls of whatever is passed as 'do'.

func (*SimpleModeler) PodLister

func (s *SimpleModeler) PodLister() algorithm.PodLister

PodLister returns a PodLister that will list pods that we think we have scheduled in addition to pods that we know have been scheduled.

type SystemModeler

type SystemModeler interface {
	// AssumePod assumes that the given pod exists in the system.
	// The assumtion should last until the system confirms the
	// assumtion or disconfirms it.
	AssumePod(pod *api.Pod)
	// ForgetPod removes a pod assumtion. (It won't make the model
	// show the absence of the given pod if the pod is in the scheduled
	// pods list!)
	ForgetPod(pod *api.Pod)
	ForgetPodByKey(key string)

	// For serializing calls to Assume/ForgetPod: imagine you want to add
	// a pod if and only if a bind succeeds, but also remove a pod if it is deleted.
	// TODO: if SystemModeler begins modeling things other than pods, this
	// should probably be parameterized or specialized for pods.
	LockedAction(f func())
}

SystemModeler can help scheduler produce a model of the system that anticipates reality. For example, if scheduler has pods A and B both using hostPort 80, when it binds A to machine M it should not bind B to machine M in the time when it hasn't observed the binding of A take effect yet.

Since the model is only an optimization, it's expected to handle any errors itself without sending them back to the scheduler.