Package org.apache.pekko.stream.scaladsl

Class RestartSource

java.lang.Object
org.apache.pekko.stream.scaladsl.RestartSource
public class RestartSource extends 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 Details

    • RestartSource

      public RestartSource()

  • Method Details

    • withBackoff

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

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

    • onFailuresWithBackoff

      public static <T> Source<T,NotUsed> onFailuresWithBackoff(RestartSettings settings, 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 failure as long as maxRestarts is not reached, since failure of the wrapped Source is handled by restarting it. 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 pekko.pattern.BackoffOpts.

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