BoundedExponentialRetryCallable.java

/**
 * Copyright 2017 Netflix, Inc.
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.raigad.utils;

import org.apache.commons.lang.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.CancellationException;

public abstract class BoundedExponentialRetryCallable<T> extends RetriableCallable<T> {
    public final static long MAX_SLEEP = 10000;
    public final static long MIN_SLEEP = 1000;
    public final static int MAX_RETRIES = 10;

    private static final Logger logger = LoggerFactory.getLogger(BoundedExponentialRetryCallable.class);

    private long max;
    private long min;
    private int maxRetries;

    private final ThreadSleeper sleeper = new ThreadSleeper();

    public BoundedExponentialRetryCallable() {
        this.max = MAX_SLEEP;
        this.min = MIN_SLEEP;
        this.maxRetries = MAX_RETRIES;
    }

    public BoundedExponentialRetryCallable(long minSleep, long maxSleep, int maxNumRetries) {
        this.max = maxSleep;
        this.min = minSleep;
        this.maxRetries = maxNumRetries;
    }

    public T call() throws Exception {
        long delay = min;// ms
        int retry = 0;
        int logCounter = 0;
        while (true) {
            try {
                return retriableCall();
            } catch (CancellationException e) {
                throw e;
            } catch (Exception e) {
                retry++;

                if (delay < max && retry <= maxRetries) {
                    delay *= 2;
                    logger.error(String.format("Retry #%d for: %s", retry, e.getMessage()));
                    if (++logCounter == 1) {
                        logger.info("Exception --> " + ExceptionUtils.getFullStackTrace(e));
                    }
                    sleeper.sleep(delay);
                } else if (delay >= max && retry <= maxRetries) {
                    logger.error(String.format("Retry #%d for: %s", retry, ExceptionUtils.getFullStackTrace(e)));
                    sleeper.sleep(max);
                } else {
                    throw e;
                }
            } finally {
                forEachExecution();
            }
        }
    }

}