HDDS-1571. Create an interface for pipeline placement policy to support network topologies. (#1395)

(cherry picked from commit 753fc6703a39154ed6013e44dbae572391748906)

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/ContainerPlacementPolicy.java → hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/PlacementPolicy.java

@@ -15,7 +15,7 @@
  * the License.
  */
 
-package org.apache.hadoop.hdds.scm.container.placement.algorithms;
+package org.apache.hadoop.hdds.scm;
 
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 
@@ -23,14 +23,14 @@ import java.io.IOException;
 import java.util.List;
 
 /**
- * A ContainerPlacementPolicy support choosing datanodes to build replication
- * pipeline with specified constraints.
+ * A PlacementPolicy support choosing datanodes to build
+ * pipelines or containers with specified constraints.
  */
-public interface ContainerPlacementPolicy {
+public interface PlacementPolicy {
 
   /**
-   * Given the replication factor and size required, return set of datanodes
-   * that satisfy the nodes and size requirement.
+   * Given an initial set of datanodes and the size required,
+   * return set of datanodes that satisfy the nodes and size requirement.
    *
    * @param excludedNodes - list of nodes to be excluded.
    * @param favoredNodes - list of nodes preferred.

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/package-info.java

@@ -1,21 +0,0 @@
-/**
- * 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.hdds.scm.container.placement.algorithms;
-/**
- Contains container placement policy interface definition.
- **/

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -823,9 +823,11 @@
     </value>
     <tag>OZONE, MANAGEMENT</tag>
     <description>
-      The full name of class which implements org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy.
+      The full name of class which implements
+      org.apache.hadoop.hdds.scm.PlacementPolicy.
       The class decides which datanode will be used to host the container replica. If not set,
-      org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementRandom will be used as default value.
+      org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementRandom will be used as default
+      value.
     </description>
   </property>
   <property>

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMCommonPolicy.java → hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/SCMCommonPlacementPolicy.java

@@ -15,7 +15,7 @@
  * the License.
  */
 
-package org.apache.hadoop.hdds.scm.container.placement.algorithms;
+package org.apache.hadoop.hdds.scm;
 
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.conf.Configuration;
@@ -33,25 +33,25 @@ import java.util.Random;
 import java.util.stream.Collectors;
 
 /**
- * SCM CommonPolicy implements a set of invariants which are common
- * for all container placement policies, acts as the repository of helper
+ * This policy implements a set of invariants which are common
+ * for all basic placement policies, acts as the repository of helper
  * functions which are common to placement policies.
  */
-public abstract class SCMCommonPolicy implements ContainerPlacementPolicy {
+public abstract class SCMCommonPlacementPolicy implements PlacementPolicy {
   @VisibleForTesting
   static final Logger LOG =
-      LoggerFactory.getLogger(SCMCommonPolicy.class);
+      LoggerFactory.getLogger(SCMCommonPlacementPolicy.class);
   private final NodeManager nodeManager;
   private final Random rand;
   private final Configuration conf;
 
   /**
-   * Constructs SCM Common Policy Class.
+   * Constructor.
    *
    * @param nodeManager NodeManager
    * @param conf Configuration class.
    */
-  public SCMCommonPolicy(NodeManager nodeManager, Configuration conf) {
+  public SCMCommonPlacementPolicy(NodeManager nodeManager, Configuration conf) {
     this.nodeManager = nodeManager;
     this.rand = new Random();
     this.conf = conf;
@@ -85,7 +85,7 @@ public abstract class SCMCommonPolicy implements ContainerPlacementPolicy {
   }
 
   /**
-   * Given the replication factor and size required, return set of datanodes
+   * Given size required, return set of datanodes
    * that satisfy the nodes and size requirement.
    * <p>
    * Here are some invariants of container placement.
@@ -149,7 +149,7 @@ public abstract class SCMCommonPolicy implements ContainerPlacementPolicy {
    * @param datanodeDetails DatanodeDetails
    * @return true if we have enough space.
    */
-  boolean hasEnoughSpace(DatanodeDetails datanodeDetails,
+  public boolean hasEnoughSpace(DatanodeDetails datanodeDetails,
       long sizeRequired) {
     SCMNodeMetric nodeMetric = nodeManager.getNodeStat(datanodeDetails);
     return (nodeMetric != null) && (nodeMetric.get() != null)
@@ -164,7 +164,7 @@ public abstract class SCMCommonPolicy implements ContainerPlacementPolicy {
    * @param nodesRequired - Nodes Required
    * @param healthyNodes - List of Nodes in the result set.
    * @return List of Datanodes that can be used for placement.
-   * @throws SCMException
+   * @throws SCMException SCMException
    */
   public List<DatanodeDetails> getResultSet(
       int nodesRequired, List<DatanodeDetails> healthyNodes)
@@ -190,8 +190,7 @@ public abstract class SCMCommonPolicy implements ContainerPlacementPolicy {
 
   /**
    * Choose a datanode according to the policy, this function is implemented
-   * by the actual policy class. For example, PlacementCapacity or
-   * PlacementRandom.
+   * by the actual policy class.
    *
    * @param healthyNodes - Set of healthy nodes we can choose from.
    * @return DatanodeDetails

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/ReplicationManager.java

@@ -38,8 +38,9 @@ import org.apache.hadoop.hdds.conf.ConfigGroup;
 import org.apache.hadoop.hdds.conf.ConfigType;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.LifeCycleState;
-import org.apache.hadoop.hdds.protocol.proto.StorageContainerDatanodeProtocolProtos.ContainerReplicaProto.State;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.protocol.proto
+    .StorageContainerDatanodeProtocolProtos.ContainerReplicaProto.State;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.events.SCMEvents;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.metrics2.MetricsCollector;
@@ -85,7 +86,7 @@ public class ReplicationManager implements MetricsSource {
    * PlacementPolicy which is used to identify where a container
    * should be replicated.
    */
-  private final ContainerPlacementPolicy containerPlacement;
+  private final PlacementPolicy containerPlacement;
 
   /**
    * EventPublisher to fire Replicate and Delete container events.
@@ -131,12 +132,12 @@ public class ReplicationManager implements MetricsSource {
    *
    * @param conf OzoneConfiguration
    * @param containerManager ContainerManager
-   * @param containerPlacement ContainerPlacementPolicy
+   * @param containerPlacement PlacementPolicy
    * @param eventPublisher EventPublisher
    */
   public ReplicationManager(final ReplicationManagerConfiguration conf,
                             final ContainerManager containerManager,
-                            final ContainerPlacementPolicy containerPlacement,
+                            final PlacementPolicy containerPlacement,
                             final EventPublisher eventPublisher,
                             final LockManager<ContainerID> lockManager) {
     this.containerManager = containerManager;
@@ -474,7 +475,7 @@ public class ReplicationManager implements MetricsSource {
 
   /**
    * If the given container is under replicated, identify a new set of
-   * datanode(s) to replicate the container using ContainerPlacementPolicy
+   * datanode(s) to replicate the container using PlacementPolicy
    * and send replicate container command to the identified datanode(s).
    *
    * @param container ContainerInfo

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/ContainerPlacementPolicyFactory.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdds.scm.container.placement.algorithms;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.net.NetworkTopology;
@@ -34,22 +35,23 @@ public final class ContainerPlacementPolicyFactory {
   private static final Logger LOG =
       LoggerFactory.getLogger(ContainerPlacementPolicyFactory.class);
 
-  private static final Class<? extends ContainerPlacementPolicy>
+  private static final Class<? extends PlacementPolicy>
       OZONE_SCM_CONTAINER_PLACEMENT_IMPL_DEFAULT =
       SCMContainerPlacementRandom.class;
 
   private ContainerPlacementPolicyFactory() {
   }
 
-  public static ContainerPlacementPolicy getPolicy(Configuration conf,
-      final NodeManager nodeManager, NetworkTopology clusterMap,
-      final boolean fallback, SCMContainerPlacementMetrics metrics)
-      throws SCMException{
-    final Class<? extends ContainerPlacementPolicy> placementClass = conf
+
+  public static PlacementPolicy getPolicy(Configuration conf,
+    final NodeManager nodeManager, NetworkTopology clusterMap,
+    final boolean fallback, SCMContainerPlacementMetrics metrics)
+    throws SCMException{
+    final Class<? extends PlacementPolicy> placementClass = conf
         .getClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
             OZONE_SCM_CONTAINER_PLACEMENT_IMPL_DEFAULT,
-            ContainerPlacementPolicy.class);
-    Constructor<? extends ContainerPlacementPolicy> constructor;
+            PlacementPolicy.class);
+    Constructor<? extends PlacementPolicy> constructor;
     try {
       constructor = placementClass.getDeclaredConstructor(NodeManager.class,
           Configuration.class, NetworkTopology.class, boolean.class,

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMContainerPlacementCapacity.java

@@ -21,6 +21,7 @@ import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
+import org.apache.hadoop.hdds.scm.SCMCommonPlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.net.NetworkTopology;
@@ -65,7 +66,8 @@ import org.slf4j.LoggerFactory;
  * little or no work and the cluster will achieve a balanced distribution
  * over time.
  */
-public final class SCMContainerPlacementCapacity extends SCMCommonPolicy {
+public final class SCMContainerPlacementCapacity
+    extends SCMCommonPlacementPolicy {
   @VisibleForTesting
   static final Logger LOG =
       LoggerFactory.getLogger(SCMContainerPlacementCapacity.class);

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMContainerPlacementRackAware.java

@@ -21,6 +21,7 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
+import org.apache.hadoop.hdds.scm.SCMCommonPlacementPolicy;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.net.NetConstants;
 import org.apache.hadoop.hdds.scm.net.NetworkTopology;
@@ -45,7 +46,8 @@ import java.util.List;
  * recommend to use this if the network topology has more layers.
  * <p>
  */
-public final class SCMContainerPlacementRackAware extends SCMCommonPolicy {
+public final class SCMContainerPlacementRackAware
+    extends SCMCommonPlacementPolicy {
   @VisibleForTesting
   static final Logger LOG =
       LoggerFactory.getLogger(SCMContainerPlacementRackAware.class);
@@ -271,8 +273,8 @@ public final class SCMContainerPlacementRackAware extends SCMCommonPolicy {
         throw new SCMException("No satisfied datanode to meet the" +
             " excludedNodes and affinityNode constrains.", null);
       }
-      if (hasEnoughSpace((DatanodeDetails)node, sizeRequired)) {
-        LOG.debug("Datanode {} is chosen for container. Required size is {}",
+      if (super.hasEnoughSpace((DatanodeDetails)node, sizeRequired)) {
+        LOG.debug("Datanode {} is chosen. Required size is {}",
             node.toString(), sizeRequired);
         metrics.incrDatanodeChooseSuccessCount();
         if (isFallbacked) {

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/SCMContainerPlacementRandom.java

@@ -19,6 +19,8 @@ package org.apache.hadoop.hdds.scm.container.placement.algorithms;
 
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
+import org.apache.hadoop.hdds.scm.SCMCommonPlacementPolicy;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.net.NetworkTopology;
 import org.apache.hadoop.hdds.scm.node.NodeManager;
@@ -37,8 +39,8 @@ import java.util.List;
  * Balancer will need to support containers as a feature before this class
  * can be practically used.
  */
-public final class SCMContainerPlacementRandom extends SCMCommonPolicy
-    implements ContainerPlacementPolicy {
+public final class SCMContainerPlacementRandom extends SCMCommonPlacementPolicy
+    implements PlacementPolicy {
   @VisibleForTesting
   static final Logger LOG =
       LoggerFactory.getLogger(SCMContainerPlacementRandom.class);

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/pipeline/PipelinePlacementPolicy.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMCommonPolicy;
+import org.apache.hadoop.hdds.scm.SCMCommonPlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.net.NetworkTopology;
@@ -47,7 +47,7 @@ import java.util.stream.Collectors;
  * 3. Choose an anchor node among the viable nodes.
  * 4. Choose other nodes around the anchor node based on network topology
  */
-public final class PipelinePlacementPolicy extends SCMCommonPolicy {
+public final class PipelinePlacementPolicy extends SCMCommonPlacementPolicy {
   @VisibleForTesting
   static final Logger LOG =
       LoggerFactory.getLogger(PipelinePlacementPolicy.class);
@@ -150,33 +150,41 @@ public final class PipelinePlacementPolicy extends SCMCommonPolicy {
   public List<DatanodeDetails> chooseDatanodes(
       List<DatanodeDetails> excludedNodes, List<DatanodeDetails> favoredNodes,
       int nodesRequired, final long sizeRequired) throws SCMException {
-    // get a list of viable nodes based on criteria
+    // Get a list of viable nodes based on criteria
+    // and make sure excludedNodes are excluded from list.
     List<DatanodeDetails> healthyNodes =
         filterViableNodes(excludedNodes, nodesRequired);
-
-    List<DatanodeDetails> results = new ArrayList<>();
-
+    
     // Randomly picks nodes when all nodes are equal.
     // This happens when network topology is absent or
     // all nodes are on the same rack.
     if (checkAllNodesAreEqual(nodeManager.getClusterNetworkTopologyMap())) {
       LOG.info("All nodes are considered equal. Now randomly pick nodes. " +
           "Required nodes: {}", nodesRequired);
-      results = super.getResultSet(nodesRequired, healthyNodes);
-      if (results.size() < nodesRequired) {
-        LOG.error("Unable to find the required number of healthy nodes that " +
-                "meet the criteria. Required nodes: {}, Found nodes: {}",
-            nodesRequired, results.size());
-        throw new SCMException("Unable to find required number of nodes.",
-            SCMException.ResultCodes.FAILED_TO_FIND_SUITABLE_NODE);
-      }
-      return results;
+      return super.getResultSet(nodesRequired, healthyNodes);
+    } else {
+      // Since topology and rack awareness are available, picks nodes
+      // based on them.
+      return this.getResultSet(nodesRequired, healthyNodes);
     }
+  }
 
+  /**
+   * Get result set based on the pipeline placement algorithm which considers
+   * network topology and rack awareness.
+   * @param nodesRequired - Nodes Required
+   * @param healthyNodes - List of Nodes in the result set.
+   * @return a list of datanodes
+   * @throws SCMException SCMException
+   */
+  @Override
+  public List<DatanodeDetails> getResultSet(
+      int nodesRequired, List<DatanodeDetails> healthyNodes)
+      throws SCMException {
+    List <DatanodeDetails> results = new ArrayList<>(nodesRequired);
     // Since nodes are widely distributed, the results should be selected
     // base on distance in topology, rack awareness and load balancing.
     List<DatanodeDetails> exclude = new ArrayList<>();
-    exclude.addAll(excludedNodes);
     // First choose an anchor nodes randomly
     DatanodeDetails anchor = chooseNode(healthyNodes);
     if (anchor == null) {
@@ -193,7 +201,7 @@ public final class PipelinePlacementPolicy extends SCMCommonPolicy {
 
     // Choose the second node on different racks from anchor.
     DatanodeDetails nodeOnDifferentRack = chooseNodeBasedOnRackAwareness(
-        healthyNodes, excludedNodes,
+        healthyNodes, exclude,
         nodeManager.getClusterNetworkTopologyMap(), anchor);
     if (nodeOnDifferentRack == null) {
       LOG.error("Unable to find nodes on different racks that " +

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/pipeline/RatisPipelineProvider.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationFactor;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.client.HddsClientUtils;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementRandom;
 import org.apache.hadoop.hdds.scm.node.NodeManager;
 import org.apache.hadoop.hdds.scm.pipeline.Pipeline.PipelineState;
@@ -103,16 +103,16 @@ public class RatisPipelineProvider implements PipelineProvider {
    * @return SCM container placement policy implementation instance.
    */
   @SuppressWarnings("unchecked")
-  // TODO: should we rename ContainerPlacementPolicy to PipelinePlacementPolicy?
-  private static ContainerPlacementPolicy createContainerPlacementPolicy(
+  // TODO: should we rename PlacementPolicy to PipelinePlacementPolicy?
+  private static PlacementPolicy createContainerPlacementPolicy(
       final NodeManager nodeManager, final Configuration conf) {
-    Class<? extends ContainerPlacementPolicy> implClass =
-        (Class<? extends ContainerPlacementPolicy>) conf.getClass(
+    Class<? extends PlacementPolicy> implClass =
+        (Class<? extends PlacementPolicy>) conf.getClass(
             ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
             SCMContainerPlacementRandom.class);
 
     try {
-      Constructor<? extends ContainerPlacementPolicy> ctor =
+      Constructor<? extends PlacementPolicy> ctor =
           implClass.getDeclaredConstructor(NodeManager.class,
               Configuration.class);
       return ctor.newInstance(nodeManager, conf);
@@ -125,7 +125,7 @@ public class RatisPipelineProvider implements PipelineProvider {
 //      LOG.error("Unhandled exception occurred, Placement policy will not " +
 //          "be functional.");
       throw new IllegalArgumentException("Unable to load " +
-          "ContainerPlacementPolicy", e);
+          "PlacementPolicy", e);
     }
   }
 

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/StorageContainerManager.java

@@ -58,7 +58,7 @@ import org.apache.hadoop.hdds.scm.container.ContainerManager;
 import org.apache.hadoop.hdds.scm.container.ContainerReportHandler;
 import org.apache.hadoop.hdds.scm.container.IncrementalContainerReportHandler;
 import org.apache.hadoop.hdds.scm.container.SCMContainerManager;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.ContainerStat;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMMetrics;
 import org.apache.hadoop.hdds.scm.container.ReplicationManager;
@@ -394,7 +394,7 @@ public final class StorageContainerManager extends ServiceRuntimeInfoImpl
 
     SCMContainerPlacementMetrics placementMetrics =
         SCMContainerPlacementMetrics.create();
-    ContainerPlacementPolicy containerPlacementPolicy =
+    PlacementPolicy containerPlacementPolicy =
         ContainerPlacementPolicyFactory.getPolicy(conf, scmNodeManager,
             clusterMap, true, placementMetrics);
 

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/container/TestReplicationManager.java

@@ -27,8 +27,7 @@ import org.apache.hadoop.hdds.protocol.proto
 import org.apache.hadoop.hdds.protocol.proto
     .StorageContainerDatanodeProtocolProtos.SCMCommandProto;
 import org.apache.hadoop.hdds.scm.container.ReplicationManager.ReplicationManagerConfiguration;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms
-    .ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.events.SCMEvents;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.server.events.EventHandler;
@@ -66,7 +65,7 @@ public class TestReplicationManager {
 
   private ReplicationManager replicationManager;
   private ContainerStateManager containerStateManager;
-  private ContainerPlacementPolicy containerPlacementPolicy;
+  private PlacementPolicy containerPlacementPolicy;
   private EventQueue eventQueue;
   private DatanodeCommandHandler datanodeCommandHandler;
 
@@ -93,7 +92,7 @@ public class TestReplicationManager {
         .thenAnswer(invocation -> containerStateManager
             .getContainerReplicas((ContainerID)invocation.getArguments()[0]));
 
-    containerPlacementPolicy = Mockito.mock(ContainerPlacementPolicy.class);
+    containerPlacementPolicy = Mockito.mock(PlacementPolicy.class);
 
     Mockito.when(containerPlacementPolicy.chooseDatanodes(
         Mockito.anyListOf(DatanodeDetails.class),

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/TestContainerPlacementFactory.java

@@ -20,6 +20,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.TestUtils;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
@@ -99,7 +100,7 @@ public class TestContainerPlacementFactory {
     when(nodeManager.getNodeStat(datanodes.get(4)))
         .thenReturn(new SCMNodeMetric(storageCapacity, 70L, 30L));
 
-    ContainerPlacementPolicy policy = ContainerPlacementPolicyFactory
+    PlacementPolicy policy = ContainerPlacementPolicyFactory
         .getPolicy(conf, nodeManager, cluster, true,
             SCMContainerPlacementMetrics.create());
 
@@ -117,7 +118,7 @@ public class TestContainerPlacementFactory {
 
   @Test
   public void testDefaultPolicy() throws IOException {
-    ContainerPlacementPolicy policy = ContainerPlacementPolicyFactory
+    PlacementPolicy policy = ContainerPlacementPolicyFactory
         .getPolicy(conf, null, null, true, null);
     Assert.assertSame(SCMContainerPlacementRandom.class, policy.getClass());
   }
@@ -125,7 +126,7 @@ public class TestContainerPlacementFactory {
   /**
    * A dummy container placement implementation for test.
    */
-  public static class DummyImpl implements ContainerPlacementPolicy {
+  public static class DummyImpl implements PlacementPolicy {
     @Override
     public List<DatanodeDetails> chooseDatanodes(
         List<DatanodeDetails> excludedNodes, List<DatanodeDetails> favoredNodes,

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/node/TestContainerPlacement.java

@@ -27,8 +27,7 @@ import org.apache.hadoop.hdds.scm.TestUtils;
 import org.apache.hadoop.hdds.scm.XceiverClientManager;
 import org.apache.hadoop.hdds.scm.container.ContainerInfo;
 import org.apache.hadoop.hdds.scm.container.SCMContainerManager;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms
-    .ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms
     .SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
@@ -135,7 +134,7 @@ public class TestContainerPlacement {
     conf.set(HddsConfigKeys.OZONE_METADATA_DIRS,
         testDir.getAbsolutePath());
     conf.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
 
     SCMNodeManager nodeManager = createNodeManager(conf);
     SCMContainerManager containerManager =

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/safemode/TestSafeModeHandler.java

@@ -25,8 +25,7 @@ import org.apache.hadoop.hdds.scm.block.BlockManagerImpl;
 import org.apache.hadoop.hdds.scm.container.ContainerManager;
 import org.apache.hadoop.hdds.scm.container.ReplicationManager;
 import org.apache.hadoop.hdds.scm.container.ReplicationManager.ReplicationManagerConfiguration;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms
-    .ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.events.SCMEvents;
 import org.apache.hadoop.hdds.scm.pipeline.PipelineManager;
 import org.apache.hadoop.hdds.scm.pipeline.SCMPipelineManager;
@@ -70,7 +69,7 @@ public class TestSafeModeHandler {
         .thenReturn(new HashSet<>());
     replicationManager = new ReplicationManager(
         new ReplicationManagerConfiguration(),
-        containerManager, Mockito.mock(ContainerPlacementPolicy.class),
+        containerManager, Mockito.mock(PlacementPolicy.class),
         eventQueue, new LockManager(configuration));
     scmPipelineManager = Mockito.mock(SCMPipelineManager.class);
     blockManager = Mockito.mock(BlockManagerImpl.class);

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/TestContainerOperations.java

@@ -22,7 +22,7 @@ import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline
 import org.apache.hadoop.ipc.ProtobufRpcEngine;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.XceiverClientManager;
@@ -53,7 +53,7 @@ public class TestContainerOperations {
         containerSizeGB * OzoneConsts.GB);
     ozoneConf = new OzoneConfiguration();
     ozoneConf.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
     cluster = MiniOzoneCluster.newBuilder(ozoneConf).setNumDatanodes(1).build();
     StorageContainerLocationProtocolClientSideTranslatorPB client =
         cluster.getStorageContainerLocationClient();

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/TestContainerStateMachineIdempotency.java

@@ -29,8 +29,7 @@ import org.apache.hadoop.hdds.scm.XceiverClientManager;
 import org.apache.hadoop.hdds.scm.XceiverClientSpi;
 import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline;
 import org.apache.hadoop.hdds.scm.pipeline.Pipeline;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.
-    ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.
     SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.scm.protocolPB.
@@ -60,7 +59,7 @@ public class TestContainerStateMachineIdempotency {
   public static void init() throws Exception {
     ozoneConfig = new OzoneConfiguration();
     ozoneConfig.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
     cluster =
         MiniOzoneCluster.newBuilder(ozoneConfig).setNumDatanodes(1).build();
     cluster.waitForClusterToBeReady();

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/dn/scrubber/TestDataScrubber.java

@@ -30,7 +30,7 @@ import org.apache.hadoop.hdds.scm.container.ContainerID;
 import org.apache.hadoop.hdds.scm.container.ContainerInfo;
 import org.apache.hadoop.hdds.scm.container.ContainerManager;
 import org.apache.hadoop.hdds.scm.container.ContainerReplica;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.scm.protocolPB.StorageContainerLocationProtocolClientSideTranslatorPB;
 import org.apache.hadoop.ozone.HddsDatanodeService;
@@ -83,7 +83,7 @@ public class TestDataScrubber {
     ozoneConfig = new OzoneConfiguration();
     ozoneConfig.set(HddsConfigKeys.HDDS_CONTAINER_REPORT_INTERVAL, "1s");
     ozoneConfig.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
     cluster = MiniOzoneCluster.newBuilder(ozoneConfig).setNumDatanodes(1)
         .build();
     cluster.waitForClusterToBeReady();

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/scm/TestContainerSmallFile.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ozone.MiniOzoneCluster;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.protocolPB
@@ -59,7 +59,7 @@ public class TestContainerSmallFile {
   public static void init() throws Exception {
     ozoneConfig = new OzoneConfiguration();
     ozoneConfig.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
     cluster = MiniOzoneCluster.newBuilder(ozoneConfig).setNumDatanodes(1)
         .build();
     cluster.waitForClusterToBeReady();

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/scm/TestGetCommittedBlockLengthAndPutKey.java

@@ -31,8 +31,7 @@ import org.apache.hadoop.hdds.scm.container.common.helpers.
 import org.apache.hadoop.hdds.scm.pipeline.Pipeline;
 import org.apache.hadoop.hdds.scm.container.common.helpers.
     StorageContainerException;
-import org.apache.hadoop.hdds.scm.container.placement.algorithms.
-    ContainerPlacementPolicy;
+import org.apache.hadoop.hdds.scm.PlacementPolicy;
 import org.apache.hadoop.hdds.scm.container.placement.algorithms.
     SCMContainerPlacementCapacity;
 import org.apache.hadoop.hdds.scm.protocolPB.
@@ -62,7 +61,7 @@ public class TestGetCommittedBlockLengthAndPutKey {
   public static void init() throws Exception {
     ozoneConfig = new OzoneConfiguration();
     ozoneConfig.setClass(ScmConfigKeys.OZONE_SCM_CONTAINER_PLACEMENT_IMPL_KEY,
-        SCMContainerPlacementCapacity.class, ContainerPlacementPolicy.class);
+        SCMContainerPlacementCapacity.class, PlacementPolicy.class);
     cluster =
         MiniOzoneCluster.newBuilder(ozoneConfig).setNumDatanodes(1).build();
     cluster.waitForClusterToBeReady();