1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.hadoop.hbase.client; 19 20 import org.apache.hadoop.hbase.HConstants; 21 22 import java.util.Random; 23 24 /** 25 * Utility used by client connections such as {@link HConnection} and 26 * {@link ServerCallable} 27 */ 28 public class ConnectionUtils { 29 30 private static final Random RANDOM = new Random(); 31 /** 32 * Calculate pause time. 33 * Built on {@link HConstants#RETRY_BACKOFF}. 34 * @param pause 35 * @param tries 36 * @return How long to wait after <code>tries</code> retries 37 */ 38 public static long getPauseTime(final long pause, final int tries) { 39 int ntries = tries; 40 if (ntries >= HConstants.RETRY_BACKOFF.length) { 41 ntries = HConstants.RETRY_BACKOFF.length - 1; 42 } 43 44 long normalPause = pause * HConstants.RETRY_BACKOFF[ntries]; 45 long jitter = (long)(normalPause * RANDOM.nextFloat() * 0.01f); // 1% possible jitter 46 return normalPause + jitter; 47 } 48 }