| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.ignite.spi; |
| |
| import org.apache.ignite.internal.util.typedef.internal.S; |
| import org.apache.ignite.internal.util.typedef.internal.U; |
| |
| /** |
| * Strategy which incorporates retriable network operation, handling of totalTimeout logic. |
| * It increases startTimeout based on exponential backoff algorithm. |
| * |
| * If failure detection is enabled it relies on totalTimeout |
| * otherwise implements exponential backoff totalTimeout logic based on startTimeout, maxTimeout and retryCnt. |
| */ |
| public class ExponentialBackoffTimeoutStrategy implements TimeoutStrategy { |
| /** Default backoff coefficient to calculate next timeout based on backoff strategy. */ |
| private static final double DLFT_BACKOFF_COEFF = 2.0; |
| |
| /** Max timeout of the next try, ms. */ |
| private final long maxTimeout; |
| |
| /** Total timeout, ms. */ |
| private final long totalTimeout; |
| |
| /** Timestamp of operation start to check totalTimeout. */ |
| private final long startNanos; |
| |
| /** Current calculated timeout, ms. */ |
| private long currTimeout; |
| |
| /** |
| * Compute expected max backoff timeout based on initTimeout, maxTimeout and reconCnt and backoff coefficient. |
| * |
| * @param initTimeout Initial timeout. |
| * @param maxTimeout Max Timeout per retry. |
| * @param reconCnt Reconnection count. |
| * @return Calculated total backoff timeout. |
| */ |
| public static long totalBackoffTimeout( |
| long initTimeout, |
| long maxTimeout, |
| long reconCnt |
| ) { |
| long totalBackoffTimeout = initTimeout; |
| |
| for (int i = 1; i < reconCnt && totalBackoffTimeout < maxTimeout; i++) |
| totalBackoffTimeout += backoffTimeout(totalBackoffTimeout, maxTimeout); |
| |
| return totalBackoffTimeout; |
| } |
| |
| /** |
| * |
| * @param timeout Timeout. |
| * @param maxTimeout Maximum startTimeout for backoff function. |
| * @return Next exponential backoff timeout. |
| */ |
| public static long backoffTimeout(long timeout, long maxTimeout) { |
| return (long) Math.min(timeout * DLFT_BACKOFF_COEFF, maxTimeout); |
| } |
| |
| /** |
| * |
| * @param totalTimeout Total startTimeout. |
| * @param startTimeout Initial connection timeout. |
| * @param maxTimeout Max connection Timeout. |
| * |
| */ |
| public ExponentialBackoffTimeoutStrategy( |
| long totalTimeout, |
| long startTimeout, |
| long maxTimeout |
| ) { |
| this.totalTimeout = totalTimeout; |
| |
| this.maxTimeout = maxTimeout; |
| |
| currTimeout = startTimeout; |
| |
| startNanos = System.nanoTime(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public long nextTimeout(long timeout) throws IgniteSpiOperationTimeoutException { |
| long remainingTime = remainingTime(System.nanoTime()); |
| |
| if (remainingTime <= 0) |
| throw new IgniteSpiOperationTimeoutException("Operation timed out [timeoutStrategy= " +this +"]"); |
| |
| /* |
| If timeout is zero that means we need return current verified timeout and calculate next timeout. |
| In case of non zero we just reverify previously calculated value not to breach totalTimeout. |
| */ |
| if (timeout == 0) { |
| long prevTimeout = currTimeout; |
| |
| currTimeout = backoffTimeout(currTimeout, maxTimeout); |
| |
| return Math.min(prevTimeout, remainingTime); |
| } else |
| return Math.min(timeout, remainingTime); |
| } |
| |
| /** |
| * Returns remaining time for current totalTimeout chunk. |
| * |
| * @param curNanos Current timestamp. |
| * @return Time to wait in millis. |
| */ |
| private long remainingTime(long curNanos) { |
| return totalTimeout - U.nanosToMillis(curNanos - startNanos); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public boolean checkTimeout(long timeInFut) { |
| return remainingTime(System.nanoTime() + U.millisToNanos(timeInFut)) <= 0; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public String toString() { |
| return S.toString(ExponentialBackoffTimeoutStrategy.class, this); |
| } |
| } |