/******************************************************************************* * 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.connectionpool.impl; import java.util.Random; import java.util.concurrent.atomic.AtomicBoolean; import com.netflix.astyanax.connectionpool.ConnectionPoolConfiguration; import com.netflix.astyanax.connectionpool.RetryBackoffStrategy; public class ExponentialRetryBackoffStrategy implements RetryBackoffStrategy { private final ConnectionPoolConfiguration config; public ExponentialRetryBackoffStrategy(ConnectionPoolConfiguration config) { this.config = config; } public String toString() { return new StringBuilder().append("ExpRetry[").append("max=").append(config.getRetryMaxDelaySlice()) .append(",slot=").append(config.getRetryDelaySlice()).append(",suspend=") .append(config.getRetrySuspendWindow()).append("]").toString(); } @Override public Instance createInstance() { return new RetryBackoffStrategy.Instance() { private int c = 1; private AtomicBoolean isSuspended = new AtomicBoolean(false); private int attemptCount = 0; private long lastReconnectTime = 0; @Override public long getNextDelay() { if (isSuspended.get()) { isSuspended.set(false); return config.getRetrySuspendWindow(); } attemptCount++; if (attemptCount == 1) { if (System.currentTimeMillis() - lastReconnectTime < config.getRetrySuspendWindow()) { return config.getRetrySuspendWindow(); } } c *= 2; if (c > config.getRetryMaxDelaySlice()) c = config.getRetryMaxDelaySlice(); return (new Random().nextInt(c) + 1) * config.getRetryDelaySlice(); } @Override public int getAttemptCount() { return attemptCount; } public String toString() { return new StringBuilder().append("ExpRetry.Instance[").append(c).append(",").append(isSuspended) .append(",").append(attemptCount).append("]").toString(); } @Override public void begin() { this.attemptCount = 0; this.c = 1; } @Override public void success() { this.lastReconnectTime = System.currentTimeMillis(); } @Override public void suspend() { this.isSuspended.set(true); } }; } }