| /** |
| * 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.hadoop.mapred; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import junit.framework.TestCase; |
| |
| /** |
| * Exercise the computeFairShares method in SchedulingAlgorithms. |
| */ |
| public class TestComputeFairShares extends TestCase { |
| private List<Schedulable> scheds; |
| |
| @Override |
| protected void setUp() throws Exception { |
| scheds = new ArrayList<Schedulable>(); |
| } |
| |
| /** |
| * Basic test - pools with different demands that are all higher than their |
| * fair share (of 10 slots) should each get their fair share. |
| */ |
| public void testEqualSharing() { |
| scheds.add(new FakeSchedulable(100)); |
| scheds.add(new FakeSchedulable(50)); |
| scheds.add(new FakeSchedulable(30)); |
| scheds.add(new FakeSchedulable(20)); |
| SchedulingAlgorithms.computeFairShares(scheds, 40); |
| verifyShares(10, 10, 10, 10); |
| } |
| |
| /** |
| * In this test, pool 4 has a smaller demand than the 40 / 4 = 10 slots that |
| * it would be assigned with equal sharing. It should only get the 3 slots |
| * it demands. The other pools must then split the remaining 37 slots, but |
| * pool 3, with 11 slots demanded, is now below its share of 37/3 ~= 12.3, |
| * so it only gets 11 slots. Pools 1 and 2 split the rest and get 13 each. |
| */ |
| public void testLowDemands() { |
| scheds.add(new FakeSchedulable(100)); |
| scheds.add(new FakeSchedulable(50)); |
| scheds.add(new FakeSchedulable(11)); |
| scheds.add(new FakeSchedulable(3)); |
| SchedulingAlgorithms.computeFairShares(scheds, 40); |
| verifyShares(13, 13, 11, 3); |
| } |
| |
| /** |
| * In this test, some pools have minimum shares set. Pool 1 has a min share |
| * of 20 so it gets 20 slots. Pool 2 also has a min share of 20, but its |
| * demand is only 10 so it can only get 10 slots. The remaining pools have |
| * 10 slots to split between them. Pool 4 gets 3 slots because its demand is |
| * only 3, and pool 3 gets the remaining 7 slots. Pool 4 also had a min share |
| * of 2 slots but this should not affect the outcome. |
| */ |
| public void testMinShares() { |
| scheds.add(new FakeSchedulable(100, 20)); |
| scheds.add(new FakeSchedulable(10, 20)); |
| scheds.add(new FakeSchedulable(10, 0)); |
| scheds.add(new FakeSchedulable(3, 2)); |
| SchedulingAlgorithms.computeFairShares(scheds, 40); |
| verifyShares(20, 10, 7, 3); |
| } |
| |
| /** |
| * Basic test for weighted shares with no minimum shares and no low demands. |
| * Each pool should get slots in proportion to its weight. |
| */ |
| public void testWeightedSharing() { |
| scheds.add(new FakeSchedulable(100, 0, 2.0)); |
| scheds.add(new FakeSchedulable(50, 0, 1.0)); |
| scheds.add(new FakeSchedulable(30, 0, 1.0)); |
| scheds.add(new FakeSchedulable(20, 0, 0.5)); |
| SchedulingAlgorithms.computeFairShares(scheds, 45); |
| verifyShares(20, 10, 10, 5); |
| } |
| |
| /** |
| * Weighted sharing test where pools 1 and 2 are now given lower demands than |
| * above. Pool 1 stops at 10 slots, leaving 35. If the remaining pools split |
| * this into a 1:1:0.5 ratio, they would get 14:14:7 slots respectively, but |
| * pool 2's demand is only 11, so it only gets 11. The remaining 2 pools split |
| * the 24 slots left into a 1:0.5 ratio, getting 16 and 8 slots respectively. |
| */ |
| public void testWeightedSharingWithLowDemands() { |
| scheds.add(new FakeSchedulable(10, 0, 2.0)); |
| scheds.add(new FakeSchedulable(11, 0, 1.0)); |
| scheds.add(new FakeSchedulable(30, 0, 1.0)); |
| scheds.add(new FakeSchedulable(20, 0, 0.5)); |
| SchedulingAlgorithms.computeFairShares(scheds, 45); |
| verifyShares(10, 11, 16, 8); |
| } |
| |
| /** |
| * Weighted fair sharing test with min shares. As in the min share test above, |
| * pool 1 has a min share greater than its demand so it only gets its demand. |
| * Pool 3 has a min share of 15 even though its weight is very small, so it |
| * gets 15 slots. The remaining pools share the remaining 20 slots equally, |
| * getting 10 each. Pool 3's min share of 5 slots doesn't affect this. |
| */ |
| public void testWeightedSharingWithMinShares() { |
| scheds.add(new FakeSchedulable(10, 20, 2.0)); |
| scheds.add(new FakeSchedulable(11, 0, 1.0)); |
| scheds.add(new FakeSchedulable(30, 5, 1.0)); |
| scheds.add(new FakeSchedulable(20, 15, 0.5)); |
| SchedulingAlgorithms.computeFairShares(scheds, 45); |
| verifyShares(10, 10, 10, 15); |
| } |
| |
| /** |
| * Test that shares are computed accurately even when there are many more |
| * frameworks than available slots. |
| */ |
| public void testSmallShares() { |
| scheds.add(new FakeSchedulable(10)); |
| scheds.add(new FakeSchedulable(5)); |
| scheds.add(new FakeSchedulable(3)); |
| scheds.add(new FakeSchedulable(2)); |
| SchedulingAlgorithms.computeFairShares(scheds, 1); |
| verifyShares(0.25, 0.25, 0.25, 0.25); |
| } |
| |
| /** |
| * Test that shares are computed accurately even when the number of slots is |
| * very large. |
| */ |
| public void testLargeShares() { |
| int million = 1000 * 1000; |
| scheds.add(new FakeSchedulable(100 * million)); |
| scheds.add(new FakeSchedulable(50 * million)); |
| scheds.add(new FakeSchedulable(30 * million)); |
| scheds.add(new FakeSchedulable(20 * million)); |
| SchedulingAlgorithms.computeFairShares(scheds, 40 * million); |
| verifyShares(10 * million, 10 * million, 10 * million, 10 * million); |
| } |
| |
| /** |
| * Test that having a pool with 0 demand doesn't confuse the algorithm. |
| */ |
| public void testZeroDemand() { |
| scheds.add(new FakeSchedulable(100)); |
| scheds.add(new FakeSchedulable(50)); |
| scheds.add(new FakeSchedulable(30)); |
| scheds.add(new FakeSchedulable(0)); |
| SchedulingAlgorithms.computeFairShares(scheds, 30); |
| verifyShares(10, 10, 10, 0); |
| } |
| |
| /** |
| * Test that being called on an empty list doesn't confuse the algorithm. |
| */ |
| public void testEmptyList() { |
| SchedulingAlgorithms.computeFairShares(scheds, 40); |
| verifyShares(); |
| } |
| |
| /** |
| * Check that a given list of shares have been assigned to this.scheds. |
| */ |
| private void verifyShares(double... shares) { |
| assertEquals(scheds.size(), shares.length); |
| for (int i = 0; i < shares.length; i++) { |
| assertEquals(shares[i], scheds.get(i).getFairShare(), 0.01); |
| } |
| } |
| } |