Class RestartSink
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.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionwithBackoff
(RestartSettings settings, Creator<Sink<T, ?>> sinkFactory)
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Constructor Details
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RestartSink
public RestartSink()
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Method Details
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withBackoff
public static <T> Sink<T,NotUsed> withBackoff(RestartSettings settings, Creator<Sink<T, ?>> sinkFactory) Wrap the givenSink
with aSink
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 wrappedSink
is handled by restarting it. The wrappedSink
can however be completed by feeding a completion or error into thisSink
. When that happens, theSink
, if currently running, will terminate and will not be restarted. This can be triggered simply by the upstream completing, or externally by introducing aKillSwitch
right before thisSink
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, thisSink
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 configurationsinkFactory
- A factory for producing theSink
to wrap.
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