io.vertx.circuitbreaker.RetryPolicy Maven / Gradle / Ivy
/*
* Copyright (c) 2011-2022 Contributors to the Eclipse Foundation
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
* which is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
*/
package io.vertx.circuitbreaker;
import io.vertx.codegen.annotations.VertxGen;
import java.util.concurrent.ThreadLocalRandom;
import static java.lang.Math.*;
/**
* A policy for retry execution.
*/
@VertxGen
@FunctionalInterface
public interface RetryPolicy {
/**
* Create a constant delay retry policy.
*
* @param delay the constant delay in milliseconds
*/
static RetryPolicy constantDelay(long delay) {
if (delay <= 0) {
throw new IllegalArgumentException("delay must be strictly positive");
}
return (failure, retryCount) -> delay;
}
/**
* Create a linear delay retry policy.
*
* @param initialDelay the initial delay in milliseconds
* @param maxDelay maximum delay in milliseconds
*/
static RetryPolicy linearDelay(long initialDelay, long maxDelay) {
if (initialDelay <= 0) {
throw new IllegalArgumentException("initialDelay must be strictly positive");
}
if (maxDelay < initialDelay) {
throw new IllegalArgumentException("maxDelay must be greater than initialDelay");
}
return (failure, retryCount) -> min(maxDelay, initialDelay * retryCount);
}
/**
* Create an exponential delay with jitter retry policy.
*
* Based on the Full Jitter approach described in
* Exponential Backoff And Jitter.
*
* @param initialDelay the initial delay in milliseconds
* @param maxDelay maximum delay in milliseconds
*/
static RetryPolicy exponentialDelayWithJitter(long initialDelay, long maxDelay) {
if (initialDelay <= 0) {
throw new IllegalArgumentException("initialDelay must be strictly positive");
}
if (maxDelay < initialDelay) {
throw new IllegalArgumentException("maxDelay must be greater than initialDelay");
}
return (failure, retryCount) -> {
ThreadLocalRandom random = ThreadLocalRandom.current();
long delay = initialDelay * (1L << retryCount);
return random.nextLong(0, delay < 0 ? maxDelay : min(maxDelay, delay));
};
}
/**
* Compute a delay in milliseconds before retry is executed.
*
* @param failure the failure of the previous execution attempt
* @param retryCount the number of times operation has been retried already
* @return a delay in milliseconds before retry is executed
*/
long delay(Throwable failure, int retryCount);
}