YARN-7778. Merging of placement constraints defined at different levels. Contributed by Weiwei Yang.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/constraint/MemoryPlacementConstraintManager.java

@@ -24,6 +24,8 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.List;
+import java.util.ArrayList;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -33,6 +35,7 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.resource.PlacementConstraint;
+import org.apache.hadoop.yarn.api.resource.PlacementConstraints;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -236,6 +239,45 @@ public PlacementConstraint getGlobalConstraint(Set<String> sourceTags) {
     }
   }
 
+  @Override
+  public PlacementConstraint getMultilevelConstraint(ApplicationId appId,
+      Set<String> sourceTags, PlacementConstraint schedulingRequestConstraint) {
+    List<PlacementConstraint> constraints = new ArrayList<>();
+    // Add scheduling request-level constraint.
+    if (schedulingRequestConstraint != null) {
+      constraints.add(schedulingRequestConstraint);
+    }
+    // Add app-level constraint if appId is given.
+    if (appId != null && sourceTags != null
+        && !sourceTags.isEmpty()) {
+      constraints.add(getConstraint(appId, sourceTags));
+    }
+    // Add global constraint.
+    if (sourceTags != null && !sourceTags.isEmpty()) {
+      constraints.add(getGlobalConstraint(sourceTags));
+    }
+
+    // Remove all null or duplicate constraints.
+    List<PlacementConstraint.AbstractConstraint> allConstraints =
+        constraints.stream()
+            .filter(placementConstraint -> placementConstraint != null
+            && placementConstraint.getConstraintExpr() != null)
+            .map(PlacementConstraint::getConstraintExpr)
+            .distinct()
+            .collect(Collectors.toList());
+
+    // Compose an AND constraint
+    // When merge request(RC), app(AC) and global constraint(GC),
+    // we do a merge on them with CC=AND(GC, AC, RC) and returns a
+    // composite AND constraint. Subsequently we check if CC could
+    // be satisfied. This ensures that every level of constraint
+    // is satisfied.
+    PlacementConstraint.And andConstraint = PlacementConstraints.and(
+        allConstraints.toArray(new PlacementConstraint
+            .AbstractConstraint[allConstraints.size()]));
+    return andConstraint.build();
+  }
+
   @Override
   public void unregisterApplication(ApplicationId appId) {
     try {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/constraint/PlacementConstraintManager.java

@@ -104,6 +104,19 @@ PlacementConstraint getConstraint(ApplicationId appId,
    */
   PlacementConstraint getGlobalConstraint(Set<String> sourceTags);
 
+  /**
+   * Consider all levels of constraints (scheduling request, app, cluster) and
+   * return a merged constraint.
+   *
+   * @param applicationId application ID
+   * @param sourceTags a set of source allocation tags
+   * @param schedulingRequestConstraint placement constraint at scheduling
+   *          request level
+   * @return a merged placement constraint
+   */
+  PlacementConstraint getMultilevelConstraint(ApplicationId applicationId,
+      Set<String> sourceTags, PlacementConstraint schedulingRequestConstraint);
+
   /**
    * Remove the constraints that correspond to a given application.
    *

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/constraint/PlacementConstraintsUtil.java

@@ -248,22 +248,14 @@ public static boolean canSatisfyConstraints(ApplicationId applicationId,
       SchedulingRequest request, SchedulerNode schedulerNode,
       PlacementConstraintManager pcm, AllocationTagsManager atm)
       throws InvalidAllocationTagsQueryException {
-    // TODO do proper merge on different level of constraints, see YARN-7778.
+    Set<String> sourceTags = null;
-
+    PlacementConstraint pc = null;
-    // Request level constraint
+    if (request != null) {
-    PlacementConstraint constraint = request.getPlacementConstraint();
+      sourceTags = request.getAllocationTags();
-    if (constraint == null) {
+      pc = request.getPlacementConstraint();
-      // Application level constraint
-      constraint = pcm.getConstraint(applicationId,
-          request.getAllocationTags());
-      if (constraint == null) {
-        // Global level constraint
-        constraint = pcm.getGlobalConstraint(request.getAllocationTags());
-        if (constraint == null) {
-          return true;
-        }
-      }
     }
-    return canSatisfyConstraints(applicationId, constraint, schedulerNode, atm);
+    return canSatisfyConstraints(applicationId,
+        pcm.getMultilevelConstraint(applicationId, sourceTags, pc),
+        schedulerNode, atm);
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/constraint/TestPlacementConstraintManagerService.java

@@ -34,8 +34,11 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import com.google.common.collect.Sets;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.SchedulingRequest;
 import org.apache.hadoop.yarn.api.resource.PlacementConstraint;
+import org.apache.hadoop.yarn.api.resource.PlacementConstraint.And;
 import org.apache.hadoop.yarn.api.resource.PlacementConstraints;
 import org.apache.hadoop.yarn.server.utils.BuilderUtils;
 import org.junit.Assert;
@@ -179,4 +182,83 @@ public void testValidateConstraint() {
     Assert.assertTrue(pcm.validateConstraint(sourceTag1, c1));
     Assert.assertFalse(pcm.validateConstraint(sourceTag4, c1));
   }
+
+  @Test
+  public void testGetRequestConstraint() {
+    // Request Constraint(RC), App Constraint(AC), Global Constraint(GC)
+    PlacementConstraint constraint;
+    And mergedConstraint;
+    SchedulingRequest request;
+
+    // RC = c1
+    // AC = null
+    // GC = null
+    constraint = pcm.getMultilevelConstraint(appId1, null, c1);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    Assert.assertEquals(1, mergedConstraint.getChildren().size());
+    Assert.assertEquals(c1, mergedConstraint.getChildren().get(0).build());
+
+    // RC = null
+    // AC = tag1->c1, tag2->c2
+    // GC = null
+    pcm.registerApplication(appId1, constraintMap1);
+    // if the source tag in the request is not mapped to any existing
+    // registered constraint, we should get an empty AND constraint.
+    constraint = pcm.getMultilevelConstraint(appId1,
+        Sets.newHashSet("not_exist_tag"), null);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    // AND()
+    Assert.assertEquals(0, mergedConstraint.getChildren().size());
+    // if a mapping is found for a given source tag
+    constraint = pcm.getMultilevelConstraint(appId1, sourceTag1, null);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    // AND(c1)
+    Assert.assertEquals(1, mergedConstraint.getChildren().size());
+    Assert.assertEquals(c1, mergedConstraint.getChildren().get(0).build());
+    pcm.unregisterApplication(appId1);
+
+    // RC = null
+    // AC = null
+    // GC = tag1->c1
+    pcm.addGlobalConstraint(sourceTag1, c1, true);
+    constraint = pcm.getMultilevelConstraint(appId1,
+        Sets.newHashSet(sourceTag1), null);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    // AND(c1)
+    Assert.assertEquals(1, mergedConstraint.getChildren().size());
+    Assert.assertEquals(c1, mergedConstraint.getChildren().get(0).build());
+    pcm.removeGlobalConstraint(sourceTag1);
+
+    // RC = c2
+    // AC = tag1->c1, tag2->c2
+    // GC = tag1->c3
+    pcm.addGlobalConstraint(sourceTag1, c3, true);
+    pcm.registerApplication(appId1, constraintMap1);
+    // both RC, AC and GC should be respected
+    constraint = pcm.getMultilevelConstraint(appId1, sourceTag1, c2);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    // AND(c1, c2, c3)
+    Assert.assertEquals(3, mergedConstraint.getChildren().size());
+    pcm.removeGlobalConstraint(sourceTag1);
+    pcm.unregisterApplication(appId1);
+
+    // RC = c1
+    // AC = tag1->c1, tag2->c2
+    // GC = tag1->c2
+    pcm.addGlobalConstraint(sourceTag1, c2, true);
+    pcm.registerApplication(appId1, constraintMap1);
+    constraint = pcm.getMultilevelConstraint(appId1,
+        Sets.newHashSet(sourceTag1), c1);
+    Assert.assertTrue(constraint.getConstraintExpr() instanceof And);
+    mergedConstraint = (And) constraint.getConstraintExpr();
+    // AND(c1, c2)
+    Assert.assertEquals(2, mergedConstraint.getChildren().size());
+    pcm.removeGlobalConstraint(sourceTag1);
+    pcm.unregisterApplication(appId1);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/placement/TestSingleConstraintAppPlacementAllocator.java

@@ -36,6 +36,8 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.TestUtils;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.constraint.AllocationTagsManager;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.constraint.InvalidAllocationTagsQueryException;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.constraint.MemoryPlacementConstraintManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.constraint.PlacementConstraintManager;
 import org.apache.hadoop.yarn.server.scheduler.SchedulerRequestKey;
 import org.junit.Assert;
 import org.junit.Before;
@@ -76,10 +78,13 @@ public void setup() throws Exception {
     // Create allocation tags manager
     AllocationTagsManager allocationTagsManager = new AllocationTagsManager(
         rmContext);
+    PlacementConstraintManager placementConstraintManager =
+        new MemoryPlacementConstraintManager();
     spyAllocationTagsManager = spy(allocationTagsManager);
     schedulerRequestKey = new SchedulerRequestKey(Priority.newInstance(1), 2L,
         TestUtils.getMockContainerId(1, 1));
     rmContext.setAllocationTagsManager(spyAllocationTagsManager);
+    rmContext.setPlacementConstraintManager(placementConstraintManager);
 
     // Create allocator
     allocator = new SingleConstraintAppPlacementAllocator();