HDFS-11859. Ozone: SCM: Separate BlockLocationProtocol from ContainerLocationProtocol. Contributed by Xiaoyu Yao.

hadoop-hdfs-project/hadoop-hdfs-client/pom.xml

@@ -192,6 +192,7 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
                   <include>DatanodeContainerProtocol.proto</include>
                   <include>Ozone.proto</include>
                   <include>KeySpaceManagerProtocol.proto</include>
+                  <include>ScmBlockLocationProtocol.proto</include>
                 </includes>
               </source>
             </configuration>

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/ScmConfigKeys.java

@@ -53,10 +53,17 @@ public final class ScmConfigKeys {
   public static final String OZONE_SCM_CLIENT_PORT_KEY =
       "ozone.scm.client.port";
   public static final int OZONE_SCM_CLIENT_PORT_DEFAULT = 9860;
+
   public static final String OZONE_SCM_DATANODE_PORT_KEY =
       "ozone.scm.datanode.port";
   public static final int OZONE_SCM_DATANODE_PORT_DEFAULT = 9861;
 
+  // OZONE_KSM_PORT_DEFAULT = 9862
+  public static final String OZONE_SCM_BLOCK_CLIENT_PORT_KEY =
+      "ozone.scm.block.client.port";
+  public static final int OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT = 9863;
+
+  // Container service client
   public static final String OZONE_SCM_CLIENT_ADDRESS_KEY =
       "ozone.scm.client.address";
   public static final String OZONE_SCM_CLIENT_BIND_HOST_KEY =
@@ -64,6 +71,14 @@ public final class ScmConfigKeys {
   public static final String OZONE_SCM_CLIENT_BIND_HOST_DEFAULT =
       "0.0.0.0";
 
+  // Block service client
+  public static final String OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY =
+      "ozone.scm.block.client.address";
+  public static final String OZONE_SCM_BLOCK_CLIENT_BIND_HOST_KEY =
+      "ozone.scm.block.client.bind.host";
+  public static final String OZONE_SCM_BLOCK_CLIENT_BIND_HOST_DEFAULT =
+      "0.0.0.0";
+
   public static final String OZONE_SCM_DATANODE_ADDRESS_KEY =
       "ozone.scm.datanode.address";
   public static final String OZONE_SCM_DATANODE_BIND_HOST_KEY =

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/container/common/helpers/DeleteBlockResult.java

@@ -19,7 +19,7 @@ package org.apache.hadoop.scm.container.common.helpers;
 
 
 import static org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.DeleteScmBlockResult;
+    .ScmBlockLocationProtocolProtos.DeleteScmBlockResult;
 
 /**
  * Class wraps storage container manager block deletion results.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/protocol/ScmBlockLocationProtocol.java

@@ -60,6 +60,6 @@ public interface ScmBlockLocationProtocol {
    * @throws IOException if there is any failure.
    *
    */
-  List<DeleteBlockResult> deleteBlocks(Set<String> keys);
+  List<DeleteBlockResult> deleteBlocks(Set<String> keys) throws IOException;
 
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/protocolPB/ScmBlockLocationProtocolClientSideTranslatorPB.java

@@ -0,0 +1,186 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.scm.protocolPB;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Sets;
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ipc.ProtobufHelper;
+import org.apache.hadoop.ipc.ProtocolTranslator;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .AllocateScmBlockRequestProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .AllocateScmBlockResponseProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .DeleteScmBlocksRequestProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .DeleteScmBlocksResponseProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .DeleteScmBlockResult;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .GetScmBlockLocationsRequestProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .GetScmBlockLocationsResponseProto;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .ScmLocatedBlockProto;
+import org.apache.hadoop.scm.container.common.helpers.AllocatedBlock;
+import org.apache.hadoop.scm.container.common.helpers.DeleteBlockResult;
+import org.apache.hadoop.scm.container.common.helpers.Pipeline;
+import org.apache.hadoop.scm.protocol.ScmBlockLocationProtocol;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * This class is the client-side translator to translate the requests made on
+ * the {@link ScmBlockLocationProtocol} interface to the RPC server
+ * implementing {@link ScmBlockLocationProtocolPB}.
+ */
+@InterfaceAudience.Private
+public final class ScmBlockLocationProtocolClientSideTranslatorPB
+    implements ScmBlockLocationProtocol, ProtocolTranslator, Closeable {
+
+  /**
+   * RpcController is not used and hence is set to null.
+   */
+  private static final RpcController NULL_RPC_CONTROLLER = null;
+
+  private final ScmBlockLocationProtocolPB rpcProxy;
+
+  /**
+   * Creates a new StorageContainerLocationProtocolClientSideTranslatorPB.
+   *
+   * @param rpcProxy {@link StorageContainerLocationProtocolPB} RPC proxy
+   */
+  public ScmBlockLocationProtocolClientSideTranslatorPB(
+      ScmBlockLocationProtocolPB rpcProxy) {
+    this.rpcProxy = rpcProxy;
+  }
+
+  /**
+   * Find the set of nodes to read/write a block, as
+   * identified by the block key.  This method supports batch lookup by
+   * passing multiple keys.
+   *
+   * @param keys batch of block keys to find
+   * @return allocated blocks for each block key
+   * @throws IOException if there is any failure
+   */
+  @Override
+  public Set<AllocatedBlock> getBlockLocations(Set<String> keys)
+      throws IOException {
+    GetScmBlockLocationsRequestProto.Builder req =
+        GetScmBlockLocationsRequestProto.newBuilder();
+    for (String key : keys) {
+      req.addKeys(key);
+    }
+    final GetScmBlockLocationsResponseProto resp;
+    try {
+      resp = rpcProxy.getScmBlockLocations(NULL_RPC_CONTROLLER,
+          req.build());
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+    Set<AllocatedBlock> locatedBlocks =
+        Sets.newLinkedHashSetWithExpectedSize(resp.getLocatedBlocksCount());
+    for (ScmLocatedBlockProto locatedBlock : resp.getLocatedBlocksList()) {
+      locatedBlocks.add(new AllocatedBlock.Builder()
+          .setKey(locatedBlock.getKey())
+          .setPipeline(Pipeline.getFromProtoBuf(locatedBlock.getPipeline()))
+          .build());
+    }
+    return locatedBlocks;
+  }
+
+  /**
+   * Asks SCM where a block should be allocated. SCM responds with the
+   * set of datanodes that should be used creating this block.
+   * @param size - size of the block.
+   * @return allocated block accessing info (key, pipeline).
+   * @throws IOException
+   */
+  @Override
+  public AllocatedBlock allocateBlock(long size) throws IOException {
+    Preconditions.checkArgument(size > 0,
+        "block size must be greater than 0");
+
+    AllocateScmBlockRequestProto request = AllocateScmBlockRequestProto
+        .newBuilder().setSize(size).build();
+    final AllocateScmBlockResponseProto response;
+    try {
+      response = rpcProxy.allocateScmBlock(NULL_RPC_CONTROLLER, request);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+    if (response.getErrorCode() !=
+        AllocateScmBlockResponseProto.Error.success) {
+      throw new IOException(response.hasErrorMessage() ?
+          response.getErrorMessage() : "Allocate block failed.");
+    }
+    AllocatedBlock.Builder builder = new AllocatedBlock.Builder()
+        .setKey(response.getKey())
+        .setPipeline(Pipeline.getFromProtoBuf(response.getPipeline()))
+        .setShouldCreateContainer(response.getCreateContainer());
+    return builder.build();
+  }
+
+  /**
+   * Delete the set of keys specified.
+   *
+   * @param keys batch of block keys to delete.
+   * @return list of block deletion results.
+   * @throws IOException if there is any failure.
+   *
+   */
+  @Override
+  public List<DeleteBlockResult> deleteBlocks(Set<String> keys)
+      throws IOException {
+    Preconditions.checkArgument(keys == null || keys.isEmpty(),
+        "keys to be deleted cannot be null or empty");
+    DeleteScmBlocksRequestProto request = DeleteScmBlocksRequestProto
+        .newBuilder()
+        .addAllKeys(keys)
+        .build();
+    final DeleteScmBlocksResponseProto resp;
+    try {
+      resp = rpcProxy.deleteScmBlocks(NULL_RPC_CONTROLLER, request);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+    List<DeleteBlockResult> results = new ArrayList(resp.getResultsCount());
+    for (DeleteScmBlockResult result : resp.getResultsList()) {
+      results.add(new DeleteBlockResult(result.getKey(), result.getResult()));
+    }
+    return results;
+  }
+
+  @Override
+  public Object getUnderlyingProxyObject() {
+    return rpcProxy;
+  }
+
+  @Override
+  public void close() {
+    RPC.stopProxy(rpcProxy);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/scm/protocolPB/ScmBlockLocationProtocolPB.java

@@ -0,0 +1,35 @@
+/**
+ * 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.scm.protocolPB;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ipc.ProtocolInfo;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos
+    .ScmBlockLocationProtocolService;
+
+/**
+ * Protocol used from an HDFS node to StorageContainerManager.  This extends the
+ * Protocol Buffers service interface to add Hadoop-specific annotations.
+ */
+@ProtocolInfo(protocolName =
+    "org.apache.hadoop.ozone.protocol.ScmBlockLocationProtocol",
+    protocolVersion = 1)
+@InterfaceAudience.Private
+public interface ScmBlockLocationProtocolPB
+    extends ScmBlockLocationProtocolService.BlockingInterface {
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/proto/ScmBlockLocationProtocol.proto

@@ -0,0 +1,133 @@
+/**
+ * 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.
+ */
+
+/**
+ * These .proto interfaces are private and unstable.
+ * Please see http://wiki.apache.org/hadoop/Compatibility
+ * for what changes are allowed for a *unstable* .proto interface.
+ */
+
+option java_package = "org.apache.hadoop.ozone.protocol.proto";
+option java_outer_classname = "ScmBlockLocationProtocolProtos";
+option java_generic_services = true;
+option java_generate_equals_and_hash = true;
+package hadoop.hdfs;
+
+import "hdfs.proto";
+import "Ozone.proto";
+
+
+// SCM Block protocol
+/**
+ * keys - batch of block keys to find
+ */
+message GetScmBlockLocationsRequestProto {
+  repeated string keys = 1;
+}
+
+/**
+ * locatedBlocks - for each requested hash, nodes that currently host the
+ *     container for that object key hash
+ */
+message GetScmBlockLocationsResponseProto {
+  repeated ScmLocatedBlockProto locatedBlocks = 1;
+}
+
+/**
+ * Holds the nodes that currently host the blocks for a key.
+ */
+message ScmLocatedBlockProto {
+  required string key = 1;
+  required hadoop.hdfs.ozone.Pipeline pipeline = 2;
+}
+
+/**
+* Request send to SCM asking allocate block of specified size.
+*/
+message AllocateScmBlockRequestProto {
+  required uint64 size = 1;
+}
+
+/**
+ * keys - batch of block keys to deleted
+ */
+message DeleteScmBlocksRequestProto {
+  repeated string keys = 1;
+}
+
+/**
+ * deletedKeys - keys that are deleted successfully
+ */
+message DeleteScmBlocksResponseProto {
+  repeated DeleteScmBlockResult results = 1;
+}
+
+message DeleteScmBlockResult {
+  enum Result {
+    success = 1;
+    chillMode = 2;
+    errorNotFound = 3;
+    unknownFailure = 4;
+  }
+  required Result result = 1;
+  required string key = 2;
+}
+
+/**
+ * Reply from SCM indicating that the container.
+ */
+message AllocateScmBlockResponseProto {
+  enum Error {
+    success = 1;
+    errorNotEnoughSpace = 2;
+    errorSizeTooBig = 3;
+    unknownFailure = 4;
+  }
+  required Error errorCode = 1;
+  required string key = 2;
+  required hadoop.hdfs.ozone.Pipeline pipeline = 3;
+  required bool createContainer = 4;
+  optional string errorMessage = 5;
+}
+
+/**
+ * Protocol used from KeySpaceManager to StorageContainerManager.
+ * See request and response messages for details of the RPC calls.
+ */
+service ScmBlockLocationProtocolService {
+
+  /**
+   * Find the set of nodes that currently host the block, as
+   * identified by the key.  This method supports batch lookup by
+   * passing multiple keys.
+   */
+  rpc getScmBlockLocations(GetScmBlockLocationsRequestProto)
+      returns (GetScmBlockLocationsResponseProto);
+
+  /**
+   * Creates a block entry in SCM.
+   */
+  rpc allocateScmBlock(AllocateScmBlockRequestProto)
+      returns (AllocateScmBlockResponseProto);
+
+  /**
+   * Deletes one or multiple block keys from SCM.
+   */
+  rpc deleteScmBlocks(DeleteScmBlocksRequestProto)
+      returns (DeleteScmBlocksResponseProto);
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/proto/StorageContainerLocationProtocol.proto

@@ -100,78 +100,6 @@ message DeleteContainerResponseProto {
   // Empty response
 }
 
-// SCM Block protocol
-/**
- * keys - batch of block keys to find
- */
-message GetScmBlockLocationsRequestProto {
-  repeated string keys = 1;
-}
-
-/**
- * locatedBlocks - for each requested hash, nodes that currently host the
- *     container for that object key hash
- */
-message GetScmBlockLocationsResponseProto {
-  repeated ScmLocatedBlockProto locatedBlocks = 1;
-}
-
-/**
- * Holds the nodes that currently host the blocks for a key.
- */
-message ScmLocatedBlockProto {
-  required string key = 1;
-  required hadoop.hdfs.ozone.Pipeline pipeline = 2;
-}
-
-/**
-* Request send to SCM asking allocate block of specified size.
-*/
-message AllocateScmBlockRequestProto {
-  required uint64 size = 1;
-}
-
-/**
- * keys - batch of block keys to deleted
- */
-message DeleteScmBlocksRequestProto {
-  repeated string keys = 1;
-}
-
-/**
- * deletedKeys - keys that are deleted successfully
- */
-message DeleteScmBlocksResponseProto {
-  repeated DeleteScmBlockResult results = 1;
-}
-
-message DeleteScmBlockResult {
-  enum Result {
-    success = 1;
-    chillMode = 2;
-    errorNotFound = 3;
-    unknownFailure = 4;
-  }
-  required Result result = 1;
-  required string key = 2;
-}
-
-/**
- * Reply from SCM indicating that the container.
- */
-message AllocateScmBlockResponseProto {
-  enum Error {
-    success = 1;
-    errorNotEnoughSpace = 2;
-    errorSizeTooBig = 3;
-    unknownFailure = 4;
-  }
-  required Error errorCode = 1;
-  required string key = 2;
-  required hadoop.hdfs.ozone.Pipeline pipeline = 3;
-  required bool createContainer = 4;
-  optional string errorMessage = 5;
-}
 
 /**
  * Protocol used from an HDFS node to StorageContainerManager.  See the request
@@ -200,24 +128,4 @@ service StorageContainerLocationProtocolService {
    * Deletes a container in SCM.
    */
   rpc deleteContainer(DeleteContainerRequestProto) returns (DeleteContainerResponseProto);
-
-  /**
-   * Find the set of nodes that currently host the block, as
-   * identified by the key.  This method supports batch lookup by
-   * passing multiple keys.
-   */
-  rpc getScmBlockLocations(GetScmBlockLocationsRequestProto)
-      returns (GetScmBlockLocationsResponseProto);
-
-  /**
-   * Creates a block entry in SCM.
-   */
-  rpc allocateScmBlock(AllocateScmBlockRequestProto)
-      returns (AllocateScmBlockResponseProto);
-
-  /**
-   * Deletes one or multiple block keys from SCM.
-   */
-  rpc deleteScmBlocks(DeleteScmBlocksRequestProto)
-      returns (DeleteScmBlocksResponseProto);
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ObjectStoreHandler.java

@@ -35,6 +35,8 @@ import org.apache.hadoop.ksm.protocolPB
 import org.apache.hadoop.ksm.protocolPB.KeySpaceManagerProtocolPB;
 import org.apache.hadoop.ozone.OzoneClientUtils;
 import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.scm.protocolPB.ScmBlockLocationProtocolClientSideTranslatorPB;
+import org.apache.hadoop.scm.protocolPB.ScmBlockLocationProtocolPB;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -69,6 +71,8 @@ public final class ObjectStoreHandler implements Closeable {
       keySpaceManagerClient;
   private final StorageContainerLocationProtocolClientSideTranslatorPB
       storageContainerLocationClient;
+  private final ScmBlockLocationProtocolClientSideTranslatorPB
+      scmBlockLocationClient;
   private final StorageHandler storageHandler;
 
   /**
@@ -91,6 +95,7 @@ public final class ObjectStoreHandler implements Closeable {
           ProtobufRpcEngine.class);
       long scmVersion =
           RPC.getProtocolVersion(StorageContainerLocationProtocolPB.class);
+
       InetSocketAddress scmAddress =
           OzoneClientUtils.getScmAddressForClients(conf);
       this.storageContainerLocationClient =
@@ -99,6 +104,16 @@ public final class ObjectStoreHandler implements Closeable {
               scmAddress, UserGroupInformation.getCurrentUser(), conf,
               NetUtils.getDefaultSocketFactory(conf),
               Client.getRpcTimeout(conf)));
+
+      InetSocketAddress scmBlockAddress =
+          OzoneClientUtils.getScmAddressForBlockClients(conf);
+      this.scmBlockLocationClient =
+          new ScmBlockLocationProtocolClientSideTranslatorPB(
+              RPC.getProxy(ScmBlockLocationProtocolPB.class, scmVersion,
+                  scmBlockAddress, UserGroupInformation.getCurrentUser(), conf,
+                  NetUtils.getDefaultSocketFactory(conf),
+                  Client.getRpcTimeout(conf)));
+
       long ksmVersion =
           RPC.getProtocolVersion(KeySpaceManagerProtocolPB.class);
       InetSocketAddress ksmAddress = OzoneClientUtils.getKsmAddress(conf);
@@ -116,6 +131,7 @@ public final class ObjectStoreHandler implements Closeable {
       if (OzoneConsts.OZONE_HANDLER_LOCAL.equalsIgnoreCase(shType)) {
         storageHandler = new LocalStorageHandler(conf);
         this.storageContainerLocationClient = null;
+        this.scmBlockLocationClient = null;
         this.keySpaceManagerClient = null;
       } else {
         throw new IllegalArgumentException(
@@ -162,5 +178,8 @@ public final class ObjectStoreHandler implements Closeable {
     if (this.storageContainerLocationClient != null) {
       this.storageContainerLocationClient.close();
     }
+    if (this.scmBlockLocationClient != null) {
+      this.scmBlockLocationClient.close();
+    }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/OzoneClientUtils.java

@@ -151,6 +151,33 @@ public final class OzoneClientUtils {
         port.or(ScmConfigKeys.OZONE_SCM_CLIENT_PORT_DEFAULT));
   }
 
+  /**
+   * Retrieve the socket address that should be used by clients to connect
+   * to the SCM for block service.
+   *
+   * @param conf
+   * @return Target InetSocketAddress for the SCM block client endpoint.
+   */
+  public static InetSocketAddress getScmAddressForBlockClients(
+      Configuration conf) {
+    final Optional<String> host = getHostNameFromConfigKeys(conf,
+        ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY);
+
+    if (!host.isPresent()) {
+      throw new IllegalArgumentException(
+          ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY +
+          " must be defined. See" +
+          " https://wiki.apache.org/hadoop/Ozone#Configuration for details" +
+          " on configuring Ozone.");
+    }
+
+    final Optional<Integer> port = getPortNumberFromConfigKeys(conf,
+        ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY);
+
+    return NetUtils.createSocketAddr(host.get() + ":" +
+        port.or(ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT));
+  }
+
   /**
    * Retrieve the socket address that should be used by DataNodes to connect
    * to the SCM.
@@ -207,6 +234,26 @@ public final class OzoneClientUtils {
             port.or(ScmConfigKeys.OZONE_SCM_CLIENT_PORT_DEFAULT));
   }
 
+  /**
+   * Retrieve the socket address that should be used by clients to connect
+   * to the SCM Block service.
+   *
+   * @param conf
+   * @return Target InetSocketAddress for the SCM block client endpoint.
+   */
+  public static InetSocketAddress getScmBlockClientBindAddress(
+      Configuration conf) {
+    final Optional<String> host = getHostNameFromConfigKeys(conf,
+        ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_BIND_HOST_KEY);
+
+    final Optional<Integer> port = getPortNumberFromConfigKeys(conf,
+        ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY);
+
+    return NetUtils.createSocketAddr(
+        host.or(ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_BIND_HOST_DEFAULT) +
+            ":" + port.or(ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_PORT_DEFAULT));
+  }
+
   /**
    * Retrieve the socket address that should be used by DataNodes to connect
    * to the SCM.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/protocolPB/ScmBlockLocationProtocolServerSideTranslatorPB.java

@@ -0,0 +1,148 @@
+/**
+ * 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.ozone.protocolPB;
+
+import com.google.common.collect.Sets;
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.scm.container.common.helpers.AllocatedBlock;
+import org.apache.hadoop.scm.container.common.helpers.DeleteBlockResult;
+import org.apache.hadoop.scm.protocol.ScmBlockLocationProtocol;
+import org.apache.hadoop.scm.protocol.StorageContainerLocationProtocol;
+import org.apache.hadoop.scm.protocolPB.ScmBlockLocationProtocolPB;
+import org.apache.hadoop.scm.protocolPB.StorageContainerLocationProtocolPB;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.AllocateScmBlockRequestProto;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.AllocateScmBlockResponseProto;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.DeleteScmBlocksRequestProto;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.DeleteScmBlocksResponseProto;
+import static org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.DeleteScmBlockResult;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.GetScmBlockLocationsRequestProto;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.GetScmBlockLocationsResponseProto;
+import org.apache.hadoop.ozone.protocol.proto
+    .ScmBlockLocationProtocolProtos.ScmLocatedBlockProto;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * This class is the server-side translator that forwards requests received on
+ * {@link StorageContainerLocationProtocolPB} to the
+ * {@link StorageContainerLocationProtocol} server implementation.
+ */
+@InterfaceAudience.Private
+public final class ScmBlockLocationProtocolServerSideTranslatorPB
+    implements ScmBlockLocationProtocolPB {
+
+  private final ScmBlockLocationProtocol impl;
+
+  /**
+   * Creates a new ScmBlockLocationProtocolServerSideTranslatorPB.
+   *
+   * @param impl {@link ScmBlockLocationProtocol} server implementation
+   */
+  public ScmBlockLocationProtocolServerSideTranslatorPB(
+      ScmBlockLocationProtocol impl) throws IOException {
+    this.impl = impl;
+  }
+
+
+  @Override
+  public GetScmBlockLocationsResponseProto getScmBlockLocations(
+      RpcController controller, GetScmBlockLocationsRequestProto req)
+      throws ServiceException {
+    Set<String> keys = Sets.newLinkedHashSetWithExpectedSize(
+        req.getKeysCount());
+    for (String key : req.getKeysList()) {
+      keys.add(key);
+    }
+    final Set<AllocatedBlock> blocks;
+    try {
+      blocks = impl.getBlockLocations(keys);
+    } catch (IOException ex) {
+      throw new ServiceException(ex);
+    }
+    GetScmBlockLocationsResponseProto.Builder resp =
+        GetScmBlockLocationsResponseProto.newBuilder();
+    for (AllocatedBlock block: blocks) {
+      ScmLocatedBlockProto.Builder locatedBlock =
+          ScmLocatedBlockProto.newBuilder()
+              .setKey(block.getKey())
+              .setPipeline(block.getPipeline().getProtobufMessage());
+      resp.addLocatedBlocks(locatedBlock.build());
+    }
+    return resp.build();
+  }
+
+  @Override
+  public AllocateScmBlockResponseProto allocateScmBlock(
+      RpcController controller, AllocateScmBlockRequestProto request)
+      throws ServiceException {
+    try {
+      AllocatedBlock allocatedBlock =
+          impl.allocateBlock(request.getSize());
+      if (allocatedBlock != null) {
+        return
+            AllocateScmBlockResponseProto.newBuilder()
+                .setKey(allocatedBlock.getKey())
+                .setPipeline(allocatedBlock.getPipeline().getProtobufMessage())
+                .setCreateContainer(allocatedBlock.getCreateContainer())
+                .setErrorCode(AllocateScmBlockResponseProto.Error.success)
+                .build();
+      } else {
+        return AllocateScmBlockResponseProto.newBuilder()
+            .setErrorCode(AllocateScmBlockResponseProto.Error.unknownFailure)
+            .build();
+      }
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  @Override
+  public DeleteScmBlocksResponseProto deleteScmBlocks(
+      RpcController controller, DeleteScmBlocksRequestProto req)
+      throws ServiceException {
+    Set<String> keys = Sets.newLinkedHashSetWithExpectedSize(
+        req.getKeysCount());
+    for (String key : req.getKeysList()) {
+      keys.add(key);
+    }
+    DeleteScmBlocksResponseProto.Builder resp =
+        DeleteScmBlocksResponseProto.newBuilder();
+    try {
+      final List<DeleteBlockResult> results = impl.deleteBlocks(keys);
+      for (DeleteBlockResult result: results) {
+        DeleteScmBlockResult.Builder deleteResult = DeleteScmBlockResult
+            .newBuilder().setKey(result.getKey()).setResult(result.getResult());
+        resp.addResults(deleteResult.build());
+      }
+    } catch (IOException ex) {
+      throw new ServiceException(ex);
+    }
+    return resp.build();
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/protocolPB/StorageContainerLocationProtocolServerSideTranslatorPB.java

@@ -18,7 +18,6 @@
 package org.apache.hadoop.ozone.protocolPB;
 
 import java.io.IOException;
-import java.util.List;
 import java.util.Set;
 
 import com.google.common.collect.Sets;
@@ -28,10 +27,7 @@ import com.google.protobuf.ServiceException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocolPB.PBHelperClient;
-import org.apache.hadoop.scm.container.common.helpers.AllocatedBlock;
-import org.apache.hadoop.scm.container.common.helpers.DeleteBlockResult;
 import org.apache.hadoop.scm.protocol.LocatedContainer;
-import org.apache.hadoop.scm.protocol.ScmBlockLocationProtocol;
 import org.apache.hadoop.scm.protocol.StorageContainerLocationProtocol;
 import org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos
@@ -39,29 +35,12 @@ import org.apache.hadoop.ozone.protocol.proto
 import org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos
     .GetStorageContainerLocationsResponseProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos
-    .ScmLocatedBlockProto;
 import org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos.LocatedContainerProto;
 import static org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos.ContainerRequestProto;
 import org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos.ContainerResponseProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.AllocateScmBlockRequestProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.AllocateScmBlockResponseProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.DeleteScmBlocksRequestProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.DeleteScmBlocksResponseProto;
-import static org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.DeleteScmBlockResult;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.GetScmBlockLocationsRequestProto;
-import org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.GetScmBlockLocationsResponseProto;
 import org.apache.hadoop.ozone.protocol.proto
     .StorageContainerLocationProtocolProtos.GetContainerRequestProto;
 import org.apache.hadoop.ozone.protocol.proto
@@ -83,7 +62,6 @@ public final class StorageContainerLocationProtocolServerSideTranslatorPB
     implements StorageContainerLocationProtocolPB {
 
   private final StorageContainerLocationProtocol impl;
-  private final ScmBlockLocationProtocol blockImpl;
 
   /**
    * Creates a new StorageContainerLocationProtocolServerSideTranslatorPB.
@@ -91,10 +69,8 @@ public final class StorageContainerLocationProtocolServerSideTranslatorPB
    * @param impl {@link StorageContainerLocationProtocol} server implementation
    */
   public StorageContainerLocationProtocolServerSideTranslatorPB(
-      StorageContainerLocationProtocol impl,
-      ScmBlockLocationProtocol blockImpl) throws IOException {
+      StorageContainerLocationProtocol impl) throws IOException {
     this.impl = impl;
-    this.blockImpl = blockImpl;
   }
 
   @Override
@@ -170,77 +146,4 @@ public final class StorageContainerLocationProtocolServerSideTranslatorPB
       throw new ServiceException(e);
     }
   }
-
-  @Override
-  public GetScmBlockLocationsResponseProto getScmBlockLocations(
-      RpcController controller, GetScmBlockLocationsRequestProto req)
-      throws ServiceException {
-    Set<String> keys = Sets.newLinkedHashSetWithExpectedSize(
-        req.getKeysCount());
-    for (String key : req.getKeysList()) {
-      keys.add(key);
-    }
-    final Set<AllocatedBlock> blocks;
-    try {
-      blocks = blockImpl.getBlockLocations(keys);
-    } catch (IOException ex) {
-      throw new ServiceException(ex);
-    }
-    GetScmBlockLocationsResponseProto.Builder resp =
-        GetScmBlockLocationsResponseProto.newBuilder();
-    for (AllocatedBlock block: blocks) {
-      ScmLocatedBlockProto.Builder locatedBlock =
-          ScmLocatedBlockProto.newBuilder()
-              .setKey(block.getKey())
-              .setPipeline(block.getPipeline().getProtobufMessage());
-      resp.addLocatedBlocks(locatedBlock.build());
-    }
-    return resp.build();
-  }
-
-  @Override
-  public AllocateScmBlockResponseProto allocateScmBlock(
-      RpcController controller, AllocateScmBlockRequestProto request)
-      throws ServiceException {
-    try {
-      AllocatedBlock allocatedBlock =
-          blockImpl.allocateBlock(request.getSize());
-      if (allocatedBlock != null) {
-        return
-            AllocateScmBlockResponseProto.newBuilder()
-            .setKey(allocatedBlock.getKey())
-            .setPipeline(allocatedBlock.getPipeline().getProtobufMessage())
-            .setCreateContainer(allocatedBlock.getCreateContainer())
-            .setErrorCode(AllocateScmBlockResponseProto.Error.success)
-            .build();
-      } else {
-        return
-            AllocateScmBlockResponseProto.newBuilder()
-            .setErrorCode(AllocateScmBlockResponseProto.Error.unknownFailure)
-            .build();
-      }
-    } catch (IOException e) {
-      throw new ServiceException(e);
-    }
-  }
-
-  @Override
-  public DeleteScmBlocksResponseProto deleteScmBlocks(
-      RpcController controller, DeleteScmBlocksRequestProto req)
-      throws ServiceException {
-    Set<String> keys = Sets.newLinkedHashSetWithExpectedSize(
-        req.getKeysCount());
-    for (String key : req.getKeysList()) {
-      keys.add(key);
-    }
-    final List<DeleteBlockResult> results = blockImpl.deleteBlocks(keys);
-    DeleteScmBlocksResponseProto.Builder resp =
-        DeleteScmBlocksResponseProto.newBuilder();
-    for (DeleteBlockResult result: results) {
-      DeleteScmBlockResult.Builder deleteResult = DeleteScmBlockResult
-          .newBuilder().setKey(result.getKey()).setResult(result.getResult());
-      resp.addResults(deleteResult.build());
-    }
-    return resp.build();
-  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/scm/StorageContainerManager.java

@@ -30,6 +30,9 @@ import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.metrics2.util.MBeans;
 import org.apache.hadoop.ozone.OzoneClientUtils;
 import org.apache.hadoop.ozone.OzoneConfiguration;
+import org.apache.hadoop.ozone.protocol.proto.ScmBlockLocationProtocolProtos;
+import org.apache.hadoop.ozone.protocolPB
+    .ScmBlockLocationProtocolServerSideTranslatorPB;
 import org.apache.hadoop.ozone.scm.block.BlockManager;
 import org.apache.hadoop.ozone.scm.block.BlockManagerImpl;
 import org.apache.hadoop.ozone.scm.exceptions.SCMException;
@@ -73,6 +76,7 @@ import org.apache.hadoop.ozone.protocol.proto
 import org.apache.hadoop.ozone.protocolPB.StorageContainerDatanodeProtocolPB;
 import org.apache.hadoop.ozone.protocolPB
     .StorageContainerDatanodeProtocolServerSideTranslatorPB;
+import org.apache.hadoop.scm.protocolPB.ScmBlockLocationProtocolPB;
 import org.apache.hadoop.scm.protocolPB.StorageContainerLocationProtocolPB;
 import org.apache.hadoop.ozone.protocolPB
     .StorageContainerLocationProtocolServerSideTranslatorPB;
@@ -97,8 +101,10 @@ import java.util.Set;
 import java.util.UUID;
 
 import static org.apache.hadoop.ozone.protocol.proto
-    .StorageContainerLocationProtocolProtos.DeleteScmBlockResult.Result;
+    .ScmBlockLocationProtocolProtos.DeleteScmBlockResult.Result;
 
+import static org.apache.hadoop.scm.ScmConfigKeys
+    .OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY;
 import static org.apache.hadoop.scm.ScmConfigKeys
     .OZONE_SCM_CLIENT_ADDRESS_KEY;
 import static org.apache.hadoop.scm.ScmConfigKeys
@@ -146,6 +152,10 @@ public class StorageContainerManager
   private final RPC.Server clientRpcServer;
   private final InetSocketAddress clientRpcAddress;
 
+  /** The RPC server that listens to requests from block service clients. */
+  private final RPC.Server blockRpcServer;
+  private final InetSocketAddress blockRpcAddress;
+
   /** SCM mxbean. */
   private ObjectName scmInfoBeanName;
 
@@ -173,6 +183,8 @@ public class StorageContainerManager
         ProtobufRpcEngine.class);
     RPC.setProtocolEngine(conf, StorageContainerLocationProtocolPB.class,
         ProtobufRpcEngine.class);
+    RPC.setProtocolEngine(conf, ScmBlockLocationProtocolPB.class,
+        ProtobufRpcEngine.class);
 
     BlockingService dnProtoPbService = StorageContainerDatanodeProtocolProtos.
         StorageContainerDatanodeProtocolService.newReflectiveBlockingService(
@@ -186,12 +198,12 @@ public class StorageContainerManager
     datanodeRpcAddress = updateListenAddress(conf,
         OZONE_SCM_DATANODE_ADDRESS_KEY, datanodeRpcAddr, datanodeRpcServer);
 
+    // SCM Container Service RPC
     BlockingService storageProtoPbService =
         StorageContainerLocationProtocolProtos
             .StorageContainerLocationProtocolService
             .newReflectiveBlockingService(
-                new StorageContainerLocationProtocolServerSideTranslatorPB(
-                    this, this));
+            new StorageContainerLocationProtocolServerSideTranslatorPB(this));
 
     final InetSocketAddress scmAddress =
         OzoneClientUtils.getScmClientBindAddress(conf);
@@ -201,6 +213,22 @@ public class StorageContainerManager
     clientRpcAddress = updateListenAddress(conf,
         OZONE_SCM_CLIENT_ADDRESS_KEY, scmAddress, clientRpcServer);
 
+
+    // SCM Block Service RPC
+    BlockingService blockProtoPbService =
+        ScmBlockLocationProtocolProtos
+            .ScmBlockLocationProtocolService
+            .newReflectiveBlockingService(
+            new ScmBlockLocationProtocolServerSideTranslatorPB(this));
+
+    final InetSocketAddress scmBlockAddress =
+        OzoneClientUtils.getScmBlockClientBindAddress(conf);
+    blockRpcServer = startRpcServer(conf, scmBlockAddress,
+        ScmBlockLocationProtocolPB.class, blockProtoPbService,
+        handlerCount);
+    blockRpcAddress = updateListenAddress(conf,
+        OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY, scmBlockAddress, blockRpcServer);
+
     registerMXBean();
   }
 
@@ -447,6 +475,9 @@ public class StorageContainerManager
     LOG.info(buildRpcServerStartMessage(
         "StorageContainerLocationProtocol RPC server", clientRpcAddress));
     clientRpcServer.start();
+    LOG.info(buildRpcServerStartMessage(
+        "ScmBlockLocationProtocol RPC server", blockRpcAddress));
+    blockRpcServer.start();
     LOG.info(buildRpcServerStartMessage("RPC server for DataNodes",
         datanodeRpcAddress));
     datanodeRpcServer.start();
@@ -456,6 +487,8 @@ public class StorageContainerManager
    * Stop service.
    */
   public void stop() {
+    LOG.info("Stopping block service RPC server");
+    blockRpcServer.stop();
     LOG.info("Stopping the StorageContainerLocationProtocol RPC server");
     clientRpcServer.stop();
     LOG.info("Stopping the RPC server for DataNodes");
@@ -470,6 +503,7 @@ public class StorageContainerManager
    */
   public void join() {
     try {
+      blockRpcServer.join();
       clientRpcServer.join();
       datanodeRpcServer.join();
     } catch (InterruptedException e) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/ozone/MiniOzoneCluster.java

@@ -351,6 +351,7 @@ public final class MiniOzoneCluster extends MiniDFSCluster
       configScmMetadata();
 
       conf.set(ScmConfigKeys.OZONE_SCM_CLIENT_ADDRESS_KEY, "127.0.0.1:0");
+      conf.set(ScmConfigKeys.OZONE_SCM_BLOCK_CLIENT_ADDRESS_KEY, "127.0.0.1:0");
       conf.set(ScmConfigKeys.OZONE_SCM_DATANODE_ADDRESS_KEY, "127.0.0.1:0");
       conf.set(KSMConfigKeys.OZONE_KSM_ADDRESS_KEY, "127.0.0.1:0");