1 /** 2 * Copyright The Apache Software Foundation 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, software 15 * distributed under the License is distributed on an "AS IS" BASIS, 16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 17 * See the License for the specific language governing permissions and 18 * limitations under the License. 19 */ 20 package org.apache.hadoop.hbase.client; 21 22 import org.apache.hadoop.hbase.testclassification.SmallTests; 23 import org.junit.Test; 24 import org.junit.experimental.categories.Category; 25 26 import java.util.Set; 27 import java.util.TreeSet; 28 29 import static org.junit.Assert.assertTrue; 30 31 @Category(SmallTests.class) 32 public class TestConnectionUtils { 33 34 @Test 35 public void testRetryTimeJitter() { 36 long[] retries = new long[200]; 37 long baseTime = 1000000; //Larger number than reality to help test randomness. 38 long maxTimeExpected = (long) (baseTime * 1.01f); 39 for (int i = 0; i < retries.length; i++) { 40 retries[i] = ConnectionUtils.getPauseTime(baseTime, 0); 41 } 42 43 Set<Long> retyTimeSet = new TreeSet<Long>(); 44 for (long l : retries) { 45 /*make sure that there is some jitter but only 1%*/ 46 assertTrue(l >= baseTime); 47 assertTrue(l <= maxTimeExpected); 48 // Add the long to the set 49 retyTimeSet.add(l); 50 } 51 52 //Make sure that most are unique. some overlap will happen 53 assertTrue(retyTimeSet.size() > (retries.length * 0.80)); 54 } 55 56 }