Package akka.stream.scaladsl

Class RestartWithBackoffFlow<In,Out>

java.lang.Object

akka.stream.stage.GraphStageWithMaterializedValue<S,NotUsed>

akka.stream.stage.GraphStage<FlowShape<In,Out>>

akka.stream.scaladsl.RestartWithBackoffFlow<In,Out>

All Implemented Interfaces:

Graph<FlowShape<In,Out>,NotUsed>

public final class RestartWithBackoffFlow<In,Out>
extends GraphStage<FlowShape<In,Out>>

Wrap the given Flow with a Flow that will restart it when it fails using an exponential backoff. Notice that this Flow will not restart on completion of the wrapped flow.

This Flow will not emit any failure The failures by the wrapped Flow will be handled by restarting the wrapping Flow as long as maxRestarts is not reached. Any termination signals sent to this Flow however will terminate the wrapped Flow, if it's running, and then the Flow will be allowed to terminate without being restarted.

The restart process is inherently lossy, since there is no coordination between cancelling and the sending of messages. A termination signal from either end of the wrapped Flow will cause the other end to be terminated, and any in transit messages will be lost. During backoff, this Flow will backpressure.

This uses the same exponential backoff algorithm as Backoff.

param: minBackoff minimum (initial) duration until the child actor will started again, if it is terminated param: maxBackoff the exponential back-off is capped to this duration param: randomFactor after calculation of the exponential back-off an additional random delay based on this factor is added, e.g. 0.2 adds up to 20% delay. In order to skip this additional delay pass in 0. param: maxRestarts the amount of restarts is capped to this amount within a time frame of minBackoff. Passing 0 will cause no restarts and a negative number will not cap the amount of restarts. param: flowFactory A factory for producing the Flow to wrap.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RestartWithBackoffFlow.Delay
static class	RestartWithBackoffFlow.Delay$

Constructor Summary

Constructors

Constructor	Description
RestartWithBackoffFlow(scala.Function0<Flow<In,Out,?>> flowFactory, scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, boolean onlyOnFailures, int maxRestarts)

Method Summary

Modifier and Type	Method	Description
RestartWithBackoffLogic<FlowShape<In,Out>>	createLogic(Attributes inheritedAttributes)
Inlet<In>	in()
Outlet<Out>	out()
FlowShape<In,Out>	shape()	The shape of a graph is all that is externally visible: its inlets and outlets.

Methods inherited from class akka.stream.stage.GraphStage

createLogicAndMaterializedValue

Methods inherited from class akka.stream.stage.GraphStageWithMaterializedValue

createLogicAndMaterializedValue, initialAttributes, traversalBuilder, withAttributes

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface akka.stream.Graph

addAttributes, async, async, async, named

Constructor Detail

RestartWithBackoffFlow

public RestartWithBackoffFlow(scala.Function0<Flow<In,Out,?>> flowFactory,
                              scala.concurrent.duration.FiniteDuration minBackoff,
                              scala.concurrent.duration.FiniteDuration maxBackoff,
                              double randomFactor,
                              boolean onlyOnFailures,
                              int maxRestarts)

Method Detail

in

public Inlet<In> in()

out

public Outlet<Out> out()

shape

public FlowShape<In,Out> shape()

Description copied from interface: Graph

The shape of a graph is all that is externally visible: its inlets and outlets.

Returns:

(undocumented)

createLogic

public RestartWithBackoffLogic<FlowShape<In,Out>> createLogic(Attributes inheritedAttributes)

Specified by:

createLogic in class GraphStage<FlowShape<In,Out>>