YARN-2475. Logic for responding to capacity drops for the ReservationSystem. Contributed by Carlo Curino and Subru Krishnan.

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carlo curino 2014-09-12 16:52:54 -07:00 committed by subru
parent aac47fda7f
commit f83a07f266
3 changed files with 249 additions and 0 deletions

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YARN-1051-CHANGES.txt Normal file
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YARN-1707. Introduce APIs to add/remove/resize queues in the
CapacityScheduler. (Carlo Curino and Subru Krishnan via curino)
YARN-2475. Logic for responding to capacity drops for the
ReservationSystem. (Carlo Curino and Subru Krishnan via curino)

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package org.apache.hadoop.yarn.server.resourcemanager.reservation;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.yarn.api.records.ReservationDefinition;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.server.resourcemanager.reservation.exceptions.PlanningException;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerConfiguration;
import org.apache.hadoop.yarn.util.Clock;
import org.apache.hadoop.yarn.util.UTCClock;
import org.apache.hadoop.yarn.util.resource.ResourceCalculator;
import org.apache.hadoop.yarn.util.resource.Resources;
import com.google.common.annotations.VisibleForTesting;
/**
* This (re)planner scan a period of time from now to a maximum time window (or
* the end of the last session, whichever comes first) checking the overall
* capacity is not violated.
*
* It greedily removes sessions in reversed order of acceptance (latest accepted
* is the first removed).
*/
public class SimpleCapacityReplanner implements Planner {
private static final Log LOG = LogFactory
.getLog(SimpleCapacityReplanner.class);
private static final Resource ZERO_RESOURCE = Resource.newInstance(0, 0);
private final Clock clock;
// this allows to control to time-span of this replanning
// far into the future time instants might be worth replanning for
// later on
private long lengthOfCheckZone;
public SimpleCapacityReplanner() {
this(new UTCClock());
}
@VisibleForTesting
SimpleCapacityReplanner(Clock clock) {
this.clock = clock;
}
@Override
public void init(String planQueueName, CapacitySchedulerConfiguration conf) {
this.lengthOfCheckZone = conf.getEnforcementWindow(planQueueName);
}
@Override
public void plan(Plan plan, List<ReservationDefinition> contracts)
throws PlanningException {
if (contracts != null) {
throw new RuntimeException(
"SimpleCapacityReplanner cannot handle new reservation contracts");
}
ResourceCalculator resCalc = plan.getResourceCalculator();
Resource totCap = plan.getTotalCapacity();
long now = clock.getTime();
// loop on all moment in time from now to the end of the check Zone
// or the end of the planned sessions whichever comes first
for (long t = now; (t < plan.getLastEndTime() && t < (now + lengthOfCheckZone)); t +=
plan.getStep()) {
Resource excessCap =
Resources.subtract(plan.getTotalCommittedResources(t), totCap);
// if we are violating
if (Resources.greaterThan(resCalc, totCap, excessCap, ZERO_RESOURCE)) {
// sorted on reverse order of acceptance, so newest reservations first
Set<ReservationAllocation> curReservations =
new TreeSet<ReservationAllocation>(plan.getReservationsAtTime(t));
for (Iterator<ReservationAllocation> resIter =
curReservations.iterator(); resIter.hasNext()
&& Resources.greaterThan(resCalc, totCap, excessCap, ZERO_RESOURCE);) {
ReservationAllocation reservation = resIter.next();
plan.deleteReservation(reservation.getReservationId());
excessCap =
Resources.subtract(excessCap, reservation.getResourcesAtTime(t));
LOG.info("Removing reservation " + reservation.getReservationId()
+ " to repair physical-resource constraints in the plan: "
+ plan.getQueueName());
}
}
}
}
}

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package org.apache.hadoop.yarn.server.resourcemanager.reservation;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import java.util.HashSet;
import java.util.Map;
import java.util.TreeMap;
import org.apache.hadoop.yarn.api.records.ReservationId;
import org.apache.hadoop.yarn.api.records.ReservationRequest;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.server.resourcemanager.reservation.exceptions.PlanningException;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerConfiguration;
import org.apache.hadoop.yarn.util.Clock;
import org.apache.hadoop.yarn.util.resource.DefaultResourceCalculator;
import org.apache.hadoop.yarn.util.resource.ResourceCalculator;
import org.junit.Test;
public class TestSimpleCapacityReplanner {
@Test
public void testReplanningPlanCapacityLoss() throws PlanningException {
Resource clusterCapacity = Resource.newInstance(100 * 1024, 10);
Resource minAlloc = Resource.newInstance(1024, 1);
Resource maxAlloc = Resource.newInstance(1024 * 8, 8);
ResourceCalculator res = new DefaultResourceCalculator();
long step = 1L;
Clock clock = mock(Clock.class);
ReservationAgent agent = mock(ReservationAgent.class);
SharingPolicy policy = new NoOverCommitPolicy();
policy.init("root.dedicated", null, new HashSet<String>());
QueueMetrics queueMetrics = mock(QueueMetrics.class);
when(clock.getTime()).thenReturn(0L);
SimpleCapacityReplanner enf = new SimpleCapacityReplanner(clock);
CapacitySchedulerConfiguration conf =
mock(CapacitySchedulerConfiguration.class);
when(conf.getEnforcementWindow(any(String.class))).thenReturn(6L);
conf.setLong(CapacitySchedulerConfiguration.PREFIX + "blah"
+ CapacitySchedulerConfiguration.DOT
+ CapacitySchedulerConfiguration.RESERVATION_ENFORCEMENT_WINDOW, 6);
enf.init("blah", conf);
// Initialize the plan with more resources
InMemoryPlan plan =
new InMemoryPlan(queueMetrics, policy, agent, clusterCapacity, step,
res, minAlloc, maxAlloc, "dedicated", enf, true, clock);
// add reservation filling the plan (separating them 1ms, so we are sure
// s2 follows s1 on acceptance
long ts = System.currentTimeMillis();
ReservationId r1 = ReservationId.newInstance(ts, 1);
int[] f5 = { 20, 20, 20, 20, 20 };
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r1, null, "u3",
"dedicated", 0, 0 + f5.length, generateAllocation(0, f5), res,
minAlloc)));
when(clock.getTime()).thenReturn(1L);
ReservationId r2 = ReservationId.newInstance(ts, 2);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r2, null, "u4",
"dedicated", 0, 0 + f5.length, generateAllocation(0, f5), res,
minAlloc)));
when(clock.getTime()).thenReturn(2L);
ReservationId r3 = ReservationId.newInstance(ts, 3);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r3, null, "u5",
"dedicated", 0, 0 + f5.length, generateAllocation(0, f5), res,
minAlloc)));
when(clock.getTime()).thenReturn(3L);
ReservationId r4 = ReservationId.newInstance(ts, 4);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r4, null, "u6",
"dedicated", 0, 0 + f5.length, generateAllocation(0, f5), res,
minAlloc)));
when(clock.getTime()).thenReturn(4L);
ReservationId r5 = ReservationId.newInstance(ts, 5);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r5, null, "u7",
"dedicated", 0, 0 + f5.length, generateAllocation(0, f5), res,
minAlloc)));
int[] f6 = { 50, 50, 50, 50, 50 };
ReservationId r6 = ReservationId.newInstance(ts, 6);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r6, null, "u3",
"dedicated", 10, 10 + f6.length, generateAllocation(10, f6), res,
minAlloc)));
when(clock.getTime()).thenReturn(6L);
ReservationId r7 = ReservationId.newInstance(ts, 7);
assertTrue(plan.toString(),
plan.addReservation(new InMemoryReservationAllocation(r7, null, "u4",
"dedicated", 10, 10 + f6.length, generateAllocation(10, f6), res,
minAlloc)));
// remove some of the resources (requires replanning)
plan.setTotalCapacity(Resource.newInstance(70 * 1024, 70));
when(clock.getTime()).thenReturn(0L);
// run the replanner
enf.plan(plan, null);
// check which reservation are still present
assertNotNull(plan.getReservationById(r1));
assertNotNull(plan.getReservationById(r2));
assertNotNull(plan.getReservationById(r3));
assertNotNull(plan.getReservationById(r6));
assertNotNull(plan.getReservationById(r7));
// and which ones are removed
assertNull(plan.getReservationById(r4));
assertNull(plan.getReservationById(r5));
// check resources at each moment in time no more exceed capacity
for (int i = 0; i < 20; i++) {
int tot = 0;
for (ReservationAllocation r : plan.getReservationsAtTime(i)) {
tot = r.getResourcesAtTime(i).getMemory();
}
assertTrue(tot <= 70 * 1024);
}
}
private Map<ReservationInterval, ReservationRequest> generateAllocation(
int startTime, int[] alloc) {
Map<ReservationInterval, ReservationRequest> req =
new TreeMap<ReservationInterval, ReservationRequest>();
for (int i = 0; i < alloc.length; i++) {
req.put(new ReservationInterval(startTime + i, startTime + i + 1),
ReservationRequest.newInstance(Resource.newInstance(1024, 1),
alloc[i]));
}
return req;
}
}