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 19 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair; 20 21 import java.util.ArrayList; 22 import java.util.List; 23 24 import org.junit.Assert; 25 26 import org.apache.hadoop.yarn.util.resource.Resources; 27 import org.apache.hadoop.yarn.server.resourcemanager.resource.ResourceType; 28 import org.apache.hadoop.yarn.server.resourcemanager.resource.ResourceWeights; 29 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.ComputeFairShares; 30 import org.junit.Before; 31 import org.junit.Test; 32 33 /** 34 * Exercise the computeFairShares method in SchedulingAlgorithms. 35 */ 36 public class TestComputeFairShares { 37 private List<Schedulable> scheds; 38 39 @Before setUp()40 public void setUp() throws Exception { 41 scheds = new ArrayList<Schedulable>(); 42 } 43 44 /** 45 * Basic test - pools with different demands that are all higher than their 46 * fair share (of 10 slots) should each get their fair share. 47 */ 48 @Test testEqualSharing()49 public void testEqualSharing() { 50 scheds.add(new FakeSchedulable()); 51 scheds.add(new FakeSchedulable()); 52 scheds.add(new FakeSchedulable()); 53 scheds.add(new FakeSchedulable()); 54 ComputeFairShares.computeShares(scheds, 55 Resources.createResource(40), ResourceType.MEMORY); 56 verifyMemoryShares(10, 10, 10, 10); 57 } 58 59 /** 60 * In this test, pool 4 has a smaller demand than the 40 / 4 = 10 slots that 61 * it would be assigned with equal sharing. It should only get the 3 slots 62 * it demands. The other pools must then split the remaining 37 slots, but 63 * pool 3, with 11 slots demanded, is now below its share of 37/3 ~= 12.3, 64 * so it only gets 11 slots. Pools 1 and 2 split the rest and get 13 each. 65 */ 66 @Test testLowMaxShares()67 public void testLowMaxShares() { 68 scheds.add(new FakeSchedulable(0, 100)); 69 scheds.add(new FakeSchedulable(0, 50)); 70 scheds.add(new FakeSchedulable(0, 11)); 71 scheds.add(new FakeSchedulable(0, 3)); 72 ComputeFairShares.computeShares(scheds, 73 Resources.createResource(40), ResourceType.MEMORY); 74 verifyMemoryShares(13, 13, 11, 3); 75 } 76 77 78 /** 79 * In this test, some pools have minimum shares set. Pool 1 has a min share 80 * of 20 so it gets 20 slots. Pool 2 also has a min share of 20, but its 81 * demand is only 10 so it can only get 10 slots. The remaining pools have 82 * 10 slots to split between them. Pool 4 gets 3 slots because its demand is 83 * only 3, and pool 3 gets the remaining 7 slots. Pool 4 also had a min share 84 * of 2 slots but this should not affect the outcome. 85 */ 86 @Test testMinShares()87 public void testMinShares() { 88 scheds.add(new FakeSchedulable(20)); 89 scheds.add(new FakeSchedulable(18)); 90 scheds.add(new FakeSchedulable(0)); 91 scheds.add(new FakeSchedulable(2)); 92 ComputeFairShares.computeShares(scheds, 93 Resources.createResource(40), ResourceType.MEMORY); 94 verifyMemoryShares(20, 18, 0, 2); 95 } 96 97 /** 98 * Basic test for weighted shares with no minimum shares and no low demands. 99 * Each pool should get slots in proportion to its weight. 100 */ 101 @Test testWeightedSharing()102 public void testWeightedSharing() { 103 scheds.add(new FakeSchedulable(0, 2.0)); 104 scheds.add(new FakeSchedulable(0, 1.0)); 105 scheds.add(new FakeSchedulable(0, 1.0)); 106 scheds.add(new FakeSchedulable(0, 0.5)); 107 ComputeFairShares.computeShares(scheds, 108 Resources.createResource(45), ResourceType.MEMORY); 109 verifyMemoryShares(20, 10, 10, 5); 110 } 111 112 /** 113 * Weighted sharing test where pools 1 and 2 are now given lower demands than 114 * above. Pool 1 stops at 10 slots, leaving 35. If the remaining pools split 115 * this into a 1:1:0.5 ratio, they would get 14:14:7 slots respectively, but 116 * pool 2's demand is only 11, so it only gets 11. The remaining 2 pools split 117 * the 24 slots left into a 1:0.5 ratio, getting 16 and 8 slots respectively. 118 */ 119 @Test testWeightedSharingWithMaxShares()120 public void testWeightedSharingWithMaxShares() { 121 scheds.add(new FakeSchedulable(0, 10, 2.0)); 122 scheds.add(new FakeSchedulable(0, 11, 1.0)); 123 scheds.add(new FakeSchedulable(0, 30, 1.0)); 124 scheds.add(new FakeSchedulable(0, 20, 0.5)); 125 ComputeFairShares.computeShares(scheds, 126 Resources.createResource(45), ResourceType.MEMORY); 127 verifyMemoryShares(10, 11, 16, 8); 128 } 129 130 131 /** 132 * Weighted fair sharing test with min shares. As in the min share test above, 133 * pool 1 has a min share greater than its demand so it only gets its demand. 134 * Pool 3 has a min share of 15 even though its weight is very small, so it 135 * gets 15 slots. The remaining pools share the remaining 20 slots equally, 136 * getting 10 each. Pool 3's min share of 5 slots doesn't affect this. 137 */ 138 @Test testWeightedSharingWithMinShares()139 public void testWeightedSharingWithMinShares() { 140 scheds.add(new FakeSchedulable(20, 2.0)); 141 scheds.add(new FakeSchedulable(0, 1.0)); 142 scheds.add(new FakeSchedulable(5, 1.0)); 143 scheds.add(new FakeSchedulable(15, 0.5)); 144 ComputeFairShares.computeShares(scheds, 145 Resources.createResource(45), ResourceType.MEMORY); 146 verifyMemoryShares(20, 5, 5, 15); 147 } 148 149 /** 150 * Test that shares are computed accurately even when the number of slots is 151 * very large. 152 */ 153 @Test testLargeShares()154 public void testLargeShares() { 155 int million = 1000 * 1000; 156 scheds.add(new FakeSchedulable()); 157 scheds.add(new FakeSchedulable()); 158 scheds.add(new FakeSchedulable()); 159 scheds.add(new FakeSchedulable()); 160 ComputeFairShares.computeShares(scheds, 161 Resources.createResource(40 * million), ResourceType.MEMORY); 162 verifyMemoryShares(10 * million, 10 * million, 10 * million, 10 * million); 163 } 164 165 /** 166 * Test that being called on an empty list doesn't confuse the algorithm. 167 */ 168 @Test testEmptyList()169 public void testEmptyList() { 170 ComputeFairShares.computeShares(scheds, 171 Resources.createResource(40), ResourceType.MEMORY); 172 verifyMemoryShares(); 173 } 174 175 /** 176 * Test that CPU works as well as memory 177 */ 178 @Test testCPU()179 public void testCPU() { 180 scheds.add(new FakeSchedulable(Resources.createResource(0, 20), 181 new ResourceWeights(2.0f))); 182 scheds.add(new FakeSchedulable(Resources.createResource(0, 0), 183 new ResourceWeights(1.0f))); 184 scheds.add(new FakeSchedulable(Resources.createResource(0, 5), 185 new ResourceWeights(1.0f))); 186 scheds.add(new FakeSchedulable(Resources.createResource(0, 15), 187 new ResourceWeights(0.5f))); 188 ComputeFairShares.computeShares(scheds, 189 Resources.createResource(0, 45), ResourceType.CPU); 190 verifyCPUShares(20, 5, 5, 15); 191 } 192 193 /** 194 * Check that a given list of shares have been assigned to this.scheds. 195 */ verifyMemoryShares(int... shares)196 private void verifyMemoryShares(int... shares) { 197 Assert.assertEquals(scheds.size(), shares.length); 198 for (int i = 0; i < shares.length; i++) { 199 Assert.assertEquals(shares[i], scheds.get(i).getFairShare().getMemory()); 200 } 201 } 202 203 /** 204 * Check that a given list of shares have been assigned to this.scheds. 205 */ verifyCPUShares(int... shares)206 private void verifyCPUShares(int... shares) { 207 Assert.assertEquals(scheds.size(), shares.length); 208 for (int i = 0; i < shares.length; i++) { 209 Assert.assertEquals(shares[i], scheds.get(i).getFairShare().getVirtualCores()); 210 } 211 } 212 } 213