Package org.apache.pekko.stream.javadsl

Class RetryFlow

java.lang.Object

org.apache.pekko.stream.javadsl.RetryFlow

public class RetryFlow
extends Object

Constructor Summary

Constructors

Constructor	Description
RetryFlow()

Method Summary

Modifier and Type	Method	Description
static <In, Out, Mat> Flow<In,Out,Mat>	withBackoff(Duration minBackoff, Duration maxBackoff, double randomFactor, int maxRetries, Flow<In,Out,Mat> flow, Function2<In,Out,Optional<In>> decideRetry)	API may change!
static <In, InCtx, Out, OutCtx, Mat> FlowWithContext<In,InCtx,Out,OutCtx,Mat>	withBackoffAndContext(Duration minBackoff, Duration maxBackoff, double randomFactor, int maxRetries, FlowWithContext<In,InCtx,Out,OutCtx,Mat> flow, Function2<Pair<In,InCtx>,Pair<Out,OutCtx>,Optional<Pair<In,InCtx>>> decideRetry)	API may change!

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RetryFlow

public RetryFlow()

Method Details

withBackoff

public static <In,
Out,
Mat> Flow<In,Out,Mat> withBackoff(Duration minBackoff,
 Duration maxBackoff,
 double randomFactor,
 int maxRetries,
 Flow<In,Out,Mat> flow,
 Function2<In,Out,Optional<In>> decideRetry)

API may change!

Allows retrying individual elements in the stream with an exponential backoff.

The retry condition is controlled by the decideRetry function. It takes the originally emitted element and the response emitted by flow, and may return a request to be retried.

The implementation of the RetryFlow requires that flow follows one-in-one-out semantics, the Flow may not filter elements, nor emit more than one element per incoming element. The RetryFlow will fail if two elements are emitted from the flow, it will be stuck "forever" if nothing is emitted. Just one element will be emitted into the flow at any time. The flow needs to emit an element before the next will be emitted to it.

Parameters:

minBackoff - minimum duration to backoff between issuing retries

maxBackoff - maximum duration to backoff between issuing retries

randomFactor - adds jitter to the retry delay. Use 0 for no jitter

flow - a flow to retry elements from

decideRetry - retry condition decision function

withBackoffAndContext

public static <In,
InCtx,
Out,
OutCtx,
Mat>
FlowWithContext<In,InCtx,Out,OutCtx,Mat> withBackoffAndContext(Duration minBackoff,
 Duration maxBackoff,
 double randomFactor,
 int maxRetries,
 FlowWithContext<In,InCtx,Out,OutCtx,Mat> flow,
 Function2<Pair<In,InCtx>,Pair<Out,OutCtx>,Optional<Pair<In,InCtx>>> decideRetry)

API may change!

Allows retrying individual elements in the stream with an exponential backoff.

The retry condition is controlled by the decideRetry function. It takes the originally emitted element with its context, and the response emitted by flow, and may return a request to be retried.

The implementation of the RetryFlow requires that flow follows one-in-one-out semantics, the FlowWithContext may not filter elements, nor emit more than one element per incoming element. The RetryFlow will fail if two elements are emitted from the flow, it will be stuck "forever" if nothing is emitted. Just one element will be emitted into the flow at any time. The flow needs to emit an element before the next will be emitted to it.

The wrapped flow and decideRetry take the additional context parameters which can be a context, or used to control retrying with other information.

Parameters:

minBackoff - minimum duration to backoff between issuing retries

maxBackoff - maximum duration to backoff between issuing retries

randomFactor - adds jitter to the retry delay. Use 0 for no jitter

flow - a flow to retry elements from

decideRetry - retry condition decision function