Class RestartSink

java.lang.Object
org.apache.pekko.stream.javadsl.RestartSink

public class RestartSink extends Object
A RestartSink wraps a Sink that gets restarted when it completes or fails.

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

  • Constructor Details

    • RestartSink

      public RestartSink()
  • Method Details

    • withBackoff

      public static <T> Sink<T,NotUsed> withBackoff(RestartSettings settings, Creator<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 pekko.pattern.BackoffOpts.

      Parameters:
      settings - RestartSettings defining restart configuration
      sinkFactory - A factory for producing the Sink to wrap.