Class RestartSource


  • public class RestartSource
    extends java.lang.Object
    A RestartSource wraps a Source that gets restarted when it completes or fails.

    They are useful for graphs that need to run for longer than the Source can necessarily guarantee it will, for example, for Source streams that depend on a remote server that may crash or become partitioned. The RestartSource ensures that the graph can continue running while the Source restarts.

    • Constructor Summary

      Constructors 
      Constructor Description
      RestartSource()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static <T> Source<T,​NotUsed> onFailuresWithBackoff​(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, int maxRestarts, scala.Function0<Source<T,​?>> sourceFactory)
      Wrap the given Source with a Source that will restart it when it fails using an exponential backoff.
      static <T> Source<T,​NotUsed> onFailuresWithBackoff​(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, scala.Function0<Source<T,​?>> sourceFactory)
      Wrap the given Source with a Source that will restart it when it fails using an exponential backoff.
      static <T> Source<T,​NotUsed> withBackoff​(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, int maxRestarts, scala.Function0<Source<T,​?>> sourceFactory)
      Wrap the given Source with a Source that will restart it when it fails or complete using an exponential backoff.
      static <T> Source<T,​NotUsed> withBackoff​(scala.concurrent.duration.FiniteDuration minBackoff, scala.concurrent.duration.FiniteDuration maxBackoff, double randomFactor, scala.Function0<Source<T,​?>> sourceFactory)
      Wrap the given Source with a Source that will restart it when it fails or complete using an exponential backoff.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • RestartSource

        public RestartSource()
    • Method Detail

      • withBackoff

        public static <T> Source<T,​NotUsed> withBackoff​(scala.concurrent.duration.FiniteDuration minBackoff,
                                                              scala.concurrent.duration.FiniteDuration maxBackoff,
                                                              double randomFactor,
                                                              scala.Function0<Source<T,​?>> sourceFactory)
        Wrap the given Source with a Source that will restart it when it fails or complete using an exponential backoff.

        This Source will never emit a complete or failure, since the completion or failure of the wrapped Source is always handled by restarting it. The wrapped Source can however be cancelled by cancelling this Source. When that happens, the wrapped Source, if currently running will be cancelled, and it will not be restarted. This can be triggered simply by the downstream cancelling, or externally by introducing a KillSwitch right after this Source in the graph.

        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.
        sourceFactory - A factory for producing the Source to wrap.
        Returns:
        (undocumented)
      • withBackoff

        public static <T> Source<T,​NotUsed> withBackoff​(scala.concurrent.duration.FiniteDuration minBackoff,
                                                              scala.concurrent.duration.FiniteDuration maxBackoff,
                                                              double randomFactor,
                                                              int maxRestarts,
                                                              scala.Function0<Source<T,​?>> sourceFactory)
        Wrap the given Source with a Source that will restart it when it fails or complete using an exponential backoff.

        This Source will not emit a complete or failure as long as maxRestarts is not reached, since the completion or failure of the wrapped Source is handled by restarting it. The wrapped Source can however be cancelled by cancelling this Source. When that happens, the wrapped Source, if currently running will be cancelled, and it will not be restarted. This can be triggered simply by the downstream cancelling, or externally by introducing a KillSwitch right after this Source in the graph.

        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.
        sourceFactory - A factory for producing the Source to wrap.
        Returns:
        (undocumented)
      • onFailuresWithBackoff

        public static <T> Source<T,​NotUsed> onFailuresWithBackoff​(scala.concurrent.duration.FiniteDuration minBackoff,
                                                                        scala.concurrent.duration.FiniteDuration maxBackoff,
                                                                        double randomFactor,
                                                                        scala.Function0<Source<T,​?>> sourceFactory)
        Wrap the given Source with a Source that will restart it when it fails using an exponential backoff.

        This Source will never emit a failure, since the failure of the wrapped Source is always handled by restarting. The wrapped Source can be cancelled by cancelling this Source. When that happens, the wrapped Source, if currently running will be cancelled, and it will not be restarted. This can be triggered simply by the downstream cancelling, or externally by introducing a KillSwitch right after this Source in the graph.

        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.
        sourceFactory - A factory for producing the Source to wrap.

        Returns:
        (undocumented)
      • onFailuresWithBackoff

        public static <T> Source<T,​NotUsed> onFailuresWithBackoff​(scala.concurrent.duration.FiniteDuration minBackoff,
                                                                        scala.concurrent.duration.FiniteDuration maxBackoff,
                                                                        double randomFactor,
                                                                        int maxRestarts,
                                                                        scala.Function0<Source<T,​?>> sourceFactory)
        Wrap the given Source with a Source that will restart it when it fails using an exponential backoff.

        This Source will not emit a complete or failure as long as maxRestarts is not reached, since the completion or failure of the wrapped Source is handled by restarting it. The wrapped Source can however be cancelled by cancelling this Source. When that happens, the wrapped Source, if currently running will be cancelled, and it will not be restarted. This can be triggered simply by the downstream cancelling, or externally by introducing a KillSwitch right after this Source in the graph.

        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.
        sourceFactory - A factory for producing the Source to wrap.

        Returns:
        (undocumented)