RestartSink.withBackoff

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

Error handling

Signature

RestartSink.withBackoff

Description

Wrap the given Sink with a Sink that will restart it when it completes or fails using exponential backoff. The backoff resets back to minBackoff if there hasn’t been a restart within maxRestartsWithin (which defaults to minBackoff).

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 BackoffOpts.

See also:

Reactive Streams semantics

backpressures during backoff and when the wrapped sink backpressures

completes when upstream completes or when maxRestarts are reached within the given time limit