com.netflix.astyanax.retry.ExponentialBackoff Maven / Gradle / Ivy
/*******************************************************************************
* Copyright 2011 Netflix
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.netflix.astyanax.retry;
import java.util.Random;
import org.apache.commons.lang.builder.ToStringBuilder;
/**
* Unbounded exponential backoff will sleep a random number of intervals within an
* exponentially increasing number of intervals.
*
* @author elandau
*
*/
public class ExponentialBackoff extends SleepingRetryPolicy {
private final int MAX_SHIFT = 30;
private final Random random = new Random();
private final int baseSleepTimeMs;
public ExponentialBackoff(int baseSleepTimeMs, int maxAttempts) {
super(maxAttempts);
this.baseSleepTimeMs = baseSleepTimeMs;
}
@Override
public long getSleepTimeMs() {
int attempt = this.getAttemptCount() + 1;
if (attempt > MAX_SHIFT) {
attempt = MAX_SHIFT;
}
return baseSleepTimeMs * Math.max(1, random.nextInt(1 << attempt));
}
public int getBaseSleepTimeMs() {
return baseSleepTimeMs;
}
@Override
public RetryPolicy duplicate() {
return new ExponentialBackoff(baseSleepTimeMs, getMaxAttemptCount());
}
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}