Package org.apache.pekko.stream.scaladsl

Class RestartFlow$

java.lang.Object
org.apache.pekko.stream.scaladsl.RestartFlow$
public class RestartFlow$ extends Object
A RestartFlow wraps a Flow that gets restarted when it completes or fails.

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

  • Field Details

    • MODULE$

      public static final RestartFlow$ MODULE$
      Static reference to the singleton instance of this Scala object.

  • Constructor Details

    • RestartFlow$

      public RestartFlow$()

  • Method Details

    • withBackoff

      public <In, Out> Flow<In,Out,NotUsed> withBackoff(RestartSettings settings, scala.Function0<Flow<In,Out,?>> flowFactory)
      Wrap the given Flow with a Flow that will restart it when it fails or complete using an exponential backoff.

      This Flow will not cancel, complete or emit a failure, until the opposite end of it has been cancelled or completed. Any termination by the Flow before that time will be handled by restarting it 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 pekko.pattern.BackoffOpts.

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

    • onFailuresWithBackoff

      public <In, Out> Flow<In,Out,NotUsed> onFailuresWithBackoff(RestartSettings settings, scala.Function0<Flow<In,Out,?>> flowFactory)
      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 pekko.pattern.BackoffOpts.

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