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Documentation

Index

• Variables
• func NewCaller(cl *httpcli.Client, opts ...Option) calls.Caller
• type Caller
• type Notification
• type NotificationType
  • func (t NotificationType) String() string
• type Option
  • func AllowReconnection(v bool) Option
  • func Listener(l func(Notification)) Option
  • func MaxRedirects(mr int) Option
• type RedirectSettings
• type StateError
  • func (err StateError) Error() string

Variables

var (
	DefaultRedirectSettings = RedirectSettings{
		MaxAttempts:      9,
		MaxBackoffPeriod: 13 * time.Second,
		MinBackoffPeriod: 500 * time.Millisecond,
	}
)

var DisconnectionDetector = func(disconnect func()) mesos.ResponseDecorator {
	var disconnectOnce sync.Once
	disconnectF := func() { disconnectOnce.Do(disconnect) }
	closeF := mesos.CloseFunc(func() (_ error) { disconnectF(); return })
	return mesos.ResponseDecoratorFunc(func(resp mesos.Response) mesos.Response {
		return &mesos.ResponseWrapper{
			Response: resp,
			Decoder:  disconnectionDecoder(resp, disconnectF),
			Closer:   closeF,
		}
	})
}

DisconnectionDetector is a programmable response decorator that attempts to detect errors that should transition the state from "connected" to "disconnected". Detector implementations are expected to invoke the `disconnect` callback in order to initiate the disconnection.

The default implementation will transition to a disconnected state when:

• an error occurs while decoding an object from the subscription stream
• mesos reports an ERROR-type scheduler.Event object via the subscription stream
• an object on the stream does not decode to a *scheduler.Event (sanity check)

Consumers of this package may choose to override default behavior by overwriting the default value of this var, but should exercise caution: failure to properly transition to a disconnected state may cause subsequent Call operations to fail (without recourse).

Functions

func NewCaller

func NewCaller(cl *httpcli.Client, opts ...Option) calls.Caller

NewCaller returns a scheduler API Client in the form of a Caller. Concurrent invocations of Call upon the returned caller are safely executed in a serial fashion. It is expected that there are no other users of the given Client since its state may be modified by this impl.

Types

type Caller

type Caller interface {
	calls.Caller
	// contains filtered or unexported methods
}

Caller is the public interface a framework scheduler's should consume

type Notification

type Notification struct {
	Type NotificationType
}

Notification objects are sent to a registered client listener (see Listener) when the state of the scheduler client changes (e.g. from disconnected to connected).

type NotificationType

type NotificationType uint8

const (
	NotificationUndefined NotificationType = iota
	NotificationDisconnected
	NotificationConnected
)

func (NotificationType) String

func (t NotificationType) String() string

type Option

type Option func(*client) Option

Option is a functional configuration option type

func AllowReconnection

func AllowReconnection(v bool) Option

AllowReconnection allows a subsequent SUBSCRIBE call before a prior SUBSCRIBE has experienced a network or protocol error. Useful in concert with heartbeat detection and for other edge error cases not handled by the connection state machine.

func Listener

func Listener(l func(Notification)) Option

func MaxRedirects

func MaxRedirects(mr int) Option

MaxRedirects is a functional option that sets the maximum number of per-call HTTP redirects for a scheduler client

type RedirectSettings

type RedirectSettings struct {
	MaxAttempts      int           // per httpDo invocation
	MaxBackoffPeriod time.Duration // should be more than minBackoffPeriod
	MinBackoffPeriod time.Duration // should be less than maxBackoffPeriod
}

type StateError

type StateError string

func (StateError) Error

func (err StateError) Error() string