Merge -r 1396971:1396972 from trunk to branch-2. Fixes: YARN-146. Add unit tests for computing fair share in the fair scheduler. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1396977 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Thomas White 2012-10-11 10:30:53 +00:00
parent b14cec5cc1
commit 0aad6f2dac
3 changed files with 302 additions and 0 deletions

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@ -41,6 +41,9 @@ Release 2.0.3-alpha - Unreleased
YARN-94. Modify DistributedShell to point to main-class by default, clean up
the help message, and hard-code the AM class. (Hitesh Shah via vinodkv)
YARN-146. Add unit tests for computing fair share in the fair scheduler.
(Sandy Ryza via tomwhite)
OPTIMIZATIONS
BUG FIXES

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@ -0,0 +1,115 @@
/**
* 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.yarn.server.resourcemanager.scheduler.fair;
import org.apache.hadoop.yarn.api.records.Priority;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.server.resourcemanager.resource.Resources;
import org.apache.hadoop.yarn.util.Records;
/**
* Dummy implementation of Schedulable for unit testing.
*/
public class FakeSchedulable extends Schedulable {
private Resource demand;
private Resource usage;
private Resource minShare;
private double weight;
private Priority priority;
private long startTime;
public FakeSchedulable() {
this(0, 0, 1, 0, 0, 0);
}
public FakeSchedulable(int demand) {
this(demand, 0, 1, 0, 0, 0);
}
public FakeSchedulable(int demand, int minShare) {
this(demand, minShare, 1, 0, 0, 0);
}
public FakeSchedulable(int demand, int minShare, double weight) {
this(demand, minShare, weight, 0, 0, 0);
}
public FakeSchedulable(int demand, int minShare, double weight, int fairShare, int usage,
long startTime) {
this(Resources.createResource(demand), Resources.createResource(minShare), weight,
Resources.createResource(fairShare), Resources.createResource(usage), startTime);
}
public FakeSchedulable(Resource demand, Resource minShare, double weight, Resource fairShare,
Resource usage, long startTime) {
this.demand = demand;
this.minShare = minShare;
this.weight = weight;
setFairShare(fairShare);
this.usage = usage;
this.priority = Records.newRecord(Priority.class);
this.startTime = startTime;
}
@Override
public Resource assignContainer(FSSchedulerNode node, boolean reserved) {
return null;
}
@Override
public Resource getDemand() {
return demand;
}
@Override
public String getName() {
return "FakeSchedulable" + this.hashCode();
}
@Override
public Priority getPriority() {
return priority;
}
@Override
public Resource getResourceUsage() {
return usage;
}
@Override
public long getStartTime() {
return startTime;
}
@Override
public double getWeight() {
return weight;
}
@Override
public Resource getMinShare() {
return minShare;
}
@Override
public void redistributeShare() {}
@Override
public void updateDemand() {}
}

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@ -0,0 +1,184 @@
/**
* 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.yarn.server.resourcemanager.scheduler.fair;
import java.util.ArrayList;
import java.util.List;
import junit.framework.Assert;
import org.apache.hadoop.yarn.server.resourcemanager.resource.Resources;
import org.junit.Before;
import org.junit.Test;
/**
* Exercise the computeFairShares method in SchedulingAlgorithms.
*/
public class TestComputeFairShares {
private List<Schedulable> scheds;
@Before
public 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.
*/
@Test
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, Resources.createResource(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.
*/
@Test
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, Resources.createResource(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.
*/
@Test
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, Resources.createResource(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.
*/
@Test
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, Resources.createResource(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.
*/
@Test
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, Resources.createResource(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.
*/
@Test
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, Resources.createResource(45));
verifyShares(10, 10, 10, 15);
}
/**
* Test that shares are computed accurately even when the number of slots is
* very large.
*/
@Test
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, Resources.createResource(40 * million));
verifyShares(10 * million, 10 * million, 10 * million, 10 * million);
}
/**
* Test that having a pool with 0 demand doesn't confuse the algorithm.
*/
@Test
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, Resources.createResource(30));
verifyShares(10, 10, 10, 0);
}
/**
* Test that being called on an empty list doesn't confuse the algorithm.
*/
@Test
public void testEmptyList() {
SchedulingAlgorithms.computeFairShares(scheds, Resources.createResource(40));
verifyShares();
}
/**
* Check that a given list of shares have been assigned to this.scheds.
*/
private void verifyShares(double... shares) {
Assert.assertEquals(scheds.size(), shares.length);
for (int i = 0; i < shares.length; i++) {
Assert.assertEquals(shares[i], scheds.get(i).getFairShare().getMemory(), 0.01);
}
}
}