Package akka.stream.scaladsl

Class RestartSink

java.lang.Object

akka.stream.scaladsl.RestartSink

public class RestartSink
extends java.lang.Object

Wrap the given Sink with a Sink that will restart it when it fails or complete using an exponential backoff.

This Sink will never cancel, since cancellation by the wrapped Sink is always handled by restarting it. The wrapped Sink can however be completed by feeding a completion or error into this Sink. When that happens, the Sink, if currently running, will terminate and will not be restarted. This can be triggered simply by the upstream completing, or externally by introducing a KillSwitch right before this Sink in the graph.

The restart process is inherently lossy, since there is no coordination between cancelling and the sending of messages. When the wrapped Sink does cancel, this Sink will backpressure, however any elements already sent may have been lost.

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: sinkFactory A factory for producing the Sink to wrap.

Constructor Summary

Constructors

Constructor	Description
RestartSink()

Method Summary

Modifier and Type	Method	Description
static <T> Sink<T,NotUsed>	withBackoff(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, int maxRestarts, scala.Function0<Sink<T,?>> sinkFactory)	Wrap the given Sink with a Sink that will restart it when it fails or complete using an exponential backoff.
static <T> Sink<T,NotUsed>	withBackoff(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, scala.Function0<Sink<T,?>> sinkFactory)

Methods inherited from class java.lang.Object

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

Constructor Detail

RestartSink

public RestartSink()

Method Detail

withBackoff

public static <T> Sink<T,NotUsed> withBackoff(scala.concurrent.duration.FiniteDuration minBackoff,
                                                    scala.concurrent.duration.FiniteDuration maxBackoff,
                                                    double randomFactor,
                                                    scala.Function0<Sink<T,?>> sinkFactory)

withBackoff

public static <T> Sink<T,NotUsed> withBackoff(scala.concurrent.duration.FiniteDuration minBackoff,
                                                    scala.concurrent.duration.FiniteDuration maxBackoff,
                                                    double randomFactor,
                                                    int maxRestarts,
                                                    scala.Function0<Sink<T,?>> sinkFactory)

Wrap the given Sink with a Sink that will restart it when it fails or complete using an exponential backoff.

This Sink will not cancel as long as maxRestarts is not reached, since cancellation by the wrapped Sink is handled by restarting it. The wrapped Sink can however be completed by feeding a completion or error into this Sink. When that happens, the Sink, if currently running, will terminate and will not be restarted. This can be triggered simply by the upstream completing, or externally by introducing a KillSwitch right before this Sink in the graph.

The restart process is inherently lossy, since there is no coordination between cancelling and the sending of messages. When the wrapped Sink does cancel, this Sink will backpressure, however any elements already sent may have been lost.

This uses the same exponential backoff algorithm as Backoff.

Parameters:

minBackoff - minimum (initial) duration until the child actor will started again, if it is terminated

maxBackoff - the exponential back-off is capped to this duration

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.

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.

sinkFactory - A factory for producing the Sink to wrap.

Returns:

(undocumented)