HDFS-10646. Federation admin tool. Contributed by Inigo Goiri.

(cherry picked from commit ae27e31fbcf546481db0b0345772db2e9132372e)

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

@@ -332,6 +332,7 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
                   <include>editlog.proto</include>
                   <include>fsimage.proto</include>
                   <include>FederationProtocol.proto</include>
+                  <include>RouterProtocol.proto</include>
                 </includes>
               </source>
             </configuration>

hadoop-hdfs-project/hadoop-hdfs/src/main/bin/hdfs

@@ -31,6 +31,7 @@ function hadoop_usage
   hadoop_add_option "--hosts filename" "list of hosts to use in worker mode"
   hadoop_add_option "--workers" "turn on worker mode"
 
+<<<<<<< HEAD
   hadoop_add_subcommand "balancer" daemon "run a cluster balancing utility"
   hadoop_add_subcommand "cacheadmin" admin "configure the HDFS cache"
   hadoop_add_subcommand "classpath" client "prints the class path needed to get the hadoop jar and the required libraries"
@@ -42,6 +43,7 @@ function hadoop_usage
   hadoop_add_subcommand "diskbalancer" daemon "Distributes data evenly among disks on a given node"
   hadoop_add_subcommand "envvars" client "display computed Hadoop environment variables"
   hadoop_add_subcommand "ec" admin "run a HDFS ErasureCoding CLI"
+  hadoop_add_subcommand "federation" admin "manage Router-based federation"
   hadoop_add_subcommand "fetchdt" client "fetch a delegation token from the NameNode"
   hadoop_add_subcommand "fsck" admin "run a DFS filesystem checking utility"
   hadoop_add_subcommand "getconf" client "get config values from configuration"
@@ -181,6 +183,9 @@ function hdfscmd_case
       HADOOP_SUBCMD_SUPPORTDAEMONIZATION="true"
       HADOOP_CLASSNAME='org.apache.hadoop.hdfs.server.federation.router.Router'
     ;;
+    federation)
+      HADOOP_CLASSNAME='org.apache.hadoop.hdfs.tools.federation.RouterAdmin'
+    ;;
     secondarynamenode)
       HADOOP_SUBCMD_SUPPORTDAEMONIZATION="true"
       HADOOP_CLASSNAME='org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode'

hadoop-hdfs-project/hadoop-hdfs/src/main/bin/hdfs.cmd

@@ -59,7 +59,7 @@ if "%1" == "--loglevel" (
     )
   )
 
-  set hdfscommands=dfs namenode secondarynamenode journalnode zkfc datanode dfsadmin haadmin fsck balancer jmxget oiv oev fetchdt getconf groups snapshotDiff lsSnapshottableDir cacheadmin mover storagepolicies classpath crypto router debug
+  set hdfscommands=dfs namenode secondarynamenode journalnode zkfc datanode dfsadmin haadmin fsck balancer jmxget oiv oev fetchdt getconf groups snapshotDiff lsSnapshottableDir cacheadmin mover storagepolicies classpath crypto router federation debug
   for %%i in ( %hdfscommands% ) do (
     if %hdfs-command% == %%i set hdfscommand=true
   )
@@ -184,6 +184,11 @@ goto :eof
   set HADOOP_OPTS=%HADOOP_OPTS% %HADOOP_ROUTER_OPTS%
   goto :eof
 
+:federation
+  set CLASS=org.apache.hadoop.hdfs.tools.federation.RouterAdmin
+  set HADOOP_OPTS=%HADOOP_OPTS% %HADOOP_ROUTER_OPTS%
+  goto :eof
+
 :debug
   set CLASS=org.apache.hadoop.hdfs.tools.DebugAdmin
   goto :eof

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -1196,6 +1196,10 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final String FEDERATION_STORE_PREFIX =
       FEDERATION_ROUTER_PREFIX + "store.";
 
+  public static final String DFS_ROUTER_STORE_ENABLE =
+      FEDERATION_STORE_PREFIX + "enable";
+  public static final boolean DFS_ROUTER_STORE_ENABLE_DEFAULT = true;
+
   public static final String FEDERATION_STORE_SERIALIZER_CLASS =
       DFSConfigKeys.FEDERATION_STORE_PREFIX + "serializer";
   public static final Class<StateStoreSerializerPBImpl>
@@ -1222,6 +1226,21 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final long FEDERATION_STORE_MEMBERSHIP_EXPIRATION_MS_DEFAULT =
       TimeUnit.MINUTES.toMillis(5);
 
+  // HDFS Router-based federation admin
+  public static final String DFS_ROUTER_ADMIN_HANDLER_COUNT_KEY =
+      FEDERATION_ROUTER_PREFIX + "admin.handler.count";
+  public static final int DFS_ROUTER_ADMIN_HANDLER_COUNT_DEFAULT = 1;
+  public static final int    DFS_ROUTER_ADMIN_PORT_DEFAULT = 8111;
+  public static final String DFS_ROUTER_ADMIN_ADDRESS_KEY =
+      FEDERATION_ROUTER_PREFIX + "admin-address";
+  public static final String DFS_ROUTER_ADMIN_ADDRESS_DEFAULT =
+      "0.0.0.0:" + DFS_ROUTER_ADMIN_PORT_DEFAULT;
+  public static final String DFS_ROUTER_ADMIN_BIND_HOST_KEY =
+      FEDERATION_ROUTER_PREFIX + "admin-bind-host";
+  public static final String DFS_ROUTER_ADMIN_ENABLE =
+      FEDERATION_ROUTER_PREFIX + "admin.enable";
+  public static final boolean DFS_ROUTER_ADMIN_ENABLE_DEFAULT = true;
+
   // dfs.client.retry confs are moved to HdfsClientConfigKeys.Retry 
   @Deprecated
   public static final String  DFS_CLIENT_RETRY_POLICY_ENABLED_KEY

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

@@ -0,0 +1,44 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.protocol.proto.RouterProtocolProtos.RouterAdminProtocolService;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSelector;
+import org.apache.hadoop.ipc.ProtocolInfo;
+import org.apache.hadoop.security.KerberosInfo;
+import org.apache.hadoop.security.token.TokenInfo;
+
+/**
+ * Protocol that a clients use to communicate with the NameNode.
+ * Note: This extends the protocolbuffer service based interface to
+ * add annotations required for security.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Stable
+@KerberosInfo(
+    serverPrincipal = DFSConfigKeys.DFS_NAMENODE_KERBEROS_PRINCIPAL_KEY)
+@TokenInfo(DelegationTokenSelector.class)
+@ProtocolInfo(protocolName = HdfsConstants.CLIENT_NAMENODE_PROTOCOL_NAME,
+    protocolVersion = 1)
+public interface RouterAdminProtocolPB extends
+    RouterAdminProtocolService.BlockingInterface {
+}

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

@@ -0,0 +1,151 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.AddMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.AddMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetMountTableEntriesRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetMountTableEntriesResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RemoveMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RemoveMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.UpdateMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.UpdateMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.server.federation.router.RouterAdminServer;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.AddMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.AddMountTableEntryResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.GetMountTableEntriesRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.GetMountTableEntriesResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.RemoveMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.RemoveMountTableEntryResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.UpdateMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.UpdateMountTableEntryResponsePBImpl;
+
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+
+/**
+ * This class is used on the server side. Calls come across the wire for the for
+ * protocol {@link RouterAdminProtocolPB}. This class translates the PB data
+ * types to the native data types used inside the HDFS Router as specified in
+ * the generic RouterAdminProtocol.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Stable
+public class RouterAdminProtocolServerSideTranslatorPB implements
+    RouterAdminProtocolPB {
+
+  private final RouterAdminServer server;
+
+  /**
+   * Constructor.
+   * @param server The NN server.
+   * @throws IOException
+   */
+  public RouterAdminProtocolServerSideTranslatorPB(RouterAdminServer server)
+      throws IOException {
+    this.server = server;
+  }
+
+  @Override
+  public AddMountTableEntryResponseProto addMountTableEntry(
+      RpcController controller, AddMountTableEntryRequestProto request)
+      throws ServiceException {
+
+    try {
+      AddMountTableEntryRequest req =
+          new AddMountTableEntryRequestPBImpl(request);
+      AddMountTableEntryResponse response = server.addMountTableEntry(req);
+      AddMountTableEntryResponsePBImpl responsePB =
+          (AddMountTableEntryResponsePBImpl)response;
+      return responsePB.getProto();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  /**
+   * Remove an entry from the mount table.
+   */
+  @Override
+  public RemoveMountTableEntryResponseProto removeMountTableEntry(
+      RpcController controller, RemoveMountTableEntryRequestProto request)
+      throws ServiceException {
+    try {
+      RemoveMountTableEntryRequest req =
+          new RemoveMountTableEntryRequestPBImpl(request);
+      RemoveMountTableEntryResponse response =
+          server.removeMountTableEntry(req);
+      RemoveMountTableEntryResponsePBImpl responsePB =
+          (RemoveMountTableEntryResponsePBImpl)response;
+      return responsePB.getProto();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  /**
+   * Get matching mount table entries.
+   */
+  @Override
+  public GetMountTableEntriesResponseProto getMountTableEntries(
+      RpcController controller, GetMountTableEntriesRequestProto request)
+          throws ServiceException {
+    try {
+      GetMountTableEntriesRequest req =
+          new GetMountTableEntriesRequestPBImpl(request);
+      GetMountTableEntriesResponse response = server.getMountTableEntries(req);
+      GetMountTableEntriesResponsePBImpl responsePB =
+          (GetMountTableEntriesResponsePBImpl)response;
+      return responsePB.getProto();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  /**
+   * Update a single mount table entry.
+   */
+  @Override
+  public UpdateMountTableEntryResponseProto updateMountTableEntry(
+      RpcController controller, UpdateMountTableEntryRequestProto request)
+          throws ServiceException {
+    try {
+      UpdateMountTableEntryRequest req =
+          new UpdateMountTableEntryRequestPBImpl(request);
+      UpdateMountTableEntryResponse response =
+          server.updateMountTableEntry(req);
+      UpdateMountTableEntryResponsePBImpl responsePB =
+          (UpdateMountTableEntryResponsePBImpl)response;
+      return responsePB.getProto();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
+}

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

@@ -0,0 +1,150 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.AddMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.AddMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetMountTableEntriesRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetMountTableEntriesResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RemoveMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RemoveMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.UpdateMountTableEntryRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.UpdateMountTableEntryResponseProto;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.AddMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.AddMountTableEntryResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.GetMountTableEntriesRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.GetMountTableEntriesResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.RemoveMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.RemoveMountTableEntryResponsePBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.UpdateMountTableEntryRequestPBImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.UpdateMountTableEntryResponsePBImpl;
+import org.apache.hadoop.ipc.ProtobufHelper;
+import org.apache.hadoop.ipc.ProtocolMetaInterface;
+import org.apache.hadoop.ipc.ProtocolTranslator;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ipc.RpcClientUtil;
+
+import com.google.protobuf.ServiceException;
+
+/**
+ * This class forwards NN's ClientProtocol calls as RPC calls to the NN server
+ * while translating from the parameter types used in ClientProtocol to the
+ * new PB types.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Stable
+public class RouterAdminProtocolTranslatorPB
+    implements ProtocolMetaInterface, MountTableManager,
+    Closeable, ProtocolTranslator {
+  final private RouterAdminProtocolPB rpcProxy;
+
+  public RouterAdminProtocolTranslatorPB(RouterAdminProtocolPB proxy) {
+    rpcProxy = proxy;
+  }
+
+  @Override
+  public void close() {
+    RPC.stopProxy(rpcProxy);
+  }
+
+  @Override
+  public Object getUnderlyingProxyObject() {
+    return rpcProxy;
+  }
+
+  @Override
+  public boolean isMethodSupported(String methodName) throws IOException {
+    return RpcClientUtil.isMethodSupported(rpcProxy,
+        RouterAdminProtocolPB.class, RPC.RpcKind.RPC_PROTOCOL_BUFFER,
+        RPC.getProtocolVersion(RouterAdminProtocolPB.class), methodName);
+  }
+
+  @Override
+  public AddMountTableEntryResponse addMountTableEntry(
+      AddMountTableEntryRequest request) throws IOException {
+    AddMountTableEntryRequestPBImpl requestPB =
+        (AddMountTableEntryRequestPBImpl)request;
+    AddMountTableEntryRequestProto proto = requestPB.getProto();
+    try {
+      AddMountTableEntryResponseProto response =
+          rpcProxy.addMountTableEntry(null, proto);
+      return new AddMountTableEntryResponsePBImpl(response);
+    } catch (ServiceException e) {
+      throw new IOException(ProtobufHelper.getRemoteException(e).getMessage());
+    }
+  }
+
+  @Override
+  public UpdateMountTableEntryResponse updateMountTableEntry(
+      UpdateMountTableEntryRequest request) throws IOException {
+    UpdateMountTableEntryRequestPBImpl requestPB =
+        (UpdateMountTableEntryRequestPBImpl)request;
+    UpdateMountTableEntryRequestProto proto = requestPB.getProto();
+    try {
+      UpdateMountTableEntryResponseProto response =
+          rpcProxy.updateMountTableEntry(null, proto);
+      return new UpdateMountTableEntryResponsePBImpl(response);
+    } catch (ServiceException e) {
+      throw new IOException(ProtobufHelper.getRemoteException(e).getMessage());
+    }
+  }
+
+  @Override
+  public RemoveMountTableEntryResponse removeMountTableEntry(
+      RemoveMountTableEntryRequest request) throws IOException {
+    RemoveMountTableEntryRequestPBImpl requestPB =
+        (RemoveMountTableEntryRequestPBImpl)request;
+    RemoveMountTableEntryRequestProto proto = requestPB.getProto();
+    try {
+      RemoveMountTableEntryResponseProto responseProto =
+          rpcProxy.removeMountTableEntry(null, proto);
+      return new RemoveMountTableEntryResponsePBImpl(responseProto);
+    } catch (ServiceException e) {
+      throw new IOException(ProtobufHelper.getRemoteException(e).getMessage());
+    }
+  }
+
+  @Override
+  public GetMountTableEntriesResponse getMountTableEntries(
+      GetMountTableEntriesRequest request) throws IOException {
+    GetMountTableEntriesRequestPBImpl requestPB =
+        (GetMountTableEntriesRequestPBImpl)request;
+    GetMountTableEntriesRequestProto proto = requestPB.getProto();
+    try {
+      GetMountTableEntriesResponseProto response =
+          rpcProxy.getMountTableEntries(null, proto);
+      return new GetMountTableEntriesResponsePBImpl(response);
+    } catch (ServiceException e) {
+      throw new IOException(ProtobufHelper.getRemoteException(e).getMessage());
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/MembershipNamenodeResolver.java

@@ -61,7 +61,7 @@ public class MembershipNamenodeResolver
   /** Reference to the State Store. */
   private final StateStoreService stateStore;
   /** Membership State Store interface. */
-  private final MembershipStore membershipInterface;
+  private MembershipStore membershipInterface;
 
   /** Parent router ID. */
   private String routerId;
@@ -82,25 +82,27 @@ public class MembershipNamenodeResolver
     if (this.stateStore != null) {
       // Request cache updates from the state store
       this.stateStore.registerCacheExternal(this);
-
-      // Initialize the interface to get the membership
-      this.membershipInterface = this.stateStore.getRegisteredRecordStore(
-          MembershipStore.class);
-    } else {
-      this.membershipInterface = null;
     }
+  }
 
+  private synchronized MembershipStore getMembershipStore() throws IOException {
     if (this.membershipInterface == null) {
-      throw new IOException("State Store does not have an interface for " +
-          MembershipStore.class.getSimpleName());
+      this.membershipInterface = this.stateStore.getRegisteredRecordStore(
+          MembershipStore.class);
+      if (this.membershipInterface == null) {
+        throw new IOException("State Store does not have an interface for " +
+            MembershipStore.class.getSimpleName());
+      }
     }
+    return this.membershipInterface;
   }
 
   @Override
   public boolean loadCache(boolean force) {
     // Our cache depends on the store, update it first
     try {
-      this.membershipInterface.loadCache(force);
+      MembershipStore membership = getMembershipStore();
+      membership.loadCache(force);
     } catch (IOException e) {
       LOG.error("Cannot update membership from the State Store", e);
     }
@@ -126,8 +128,9 @@ public class MembershipNamenodeResolver
       GetNamenodeRegistrationsRequest request =
           GetNamenodeRegistrationsRequest.newInstance(partial);
 
+      MembershipStore membership = getMembershipStore();
       GetNamenodeRegistrationsResponse response =
-          this.membershipInterface.getNamenodeRegistrations(request);
+          membership.getNamenodeRegistrations(request);
       List<MembershipState> records = response.getNamenodeMemberships();
 
       if (records != null && records.size() == 1) {
@@ -135,7 +138,7 @@ public class MembershipNamenodeResolver
         UpdateNamenodeRegistrationRequest updateRequest =
             UpdateNamenodeRegistrationRequest.newInstance(
                 record.getNameserviceId(), record.getNamenodeId(), ACTIVE);
-        this.membershipInterface.updateNamenodeRegistration(updateRequest);
+        membership.updateNamenodeRegistration(updateRequest);
       }
     } catch (StateStoreUnavailableException e) {
       LOG.error("Cannot update {} as active, State Store unavailable", address);
@@ -226,14 +229,14 @@ public class MembershipNamenodeResolver
 
     NamenodeHeartbeatRequest request = NamenodeHeartbeatRequest.newInstance();
     request.setNamenodeMembership(record);
-    return this.membershipInterface.namenodeHeartbeat(request).getResult();
+    return getMembershipStore().namenodeHeartbeat(request).getResult();
   }
 
   @Override
   public Set<FederationNamespaceInfo> getNamespaces() throws IOException {
     GetNamespaceInfoRequest request = GetNamespaceInfoRequest.newInstance();
     GetNamespaceInfoResponse response =
-        this.membershipInterface.getNamespaceInfo(request);
+        getMembershipStore().getNamespaceInfo(request);
     return response.getNamespaceInfo();
   }
 
@@ -259,8 +262,9 @@ public class MembershipNamenodeResolver
     // Retrieve a list of all registrations that match this query.
     // This may include all NN records for a namespace/blockpool, including
     // duplicate records for the same NN from different routers.
+    MembershipStore membershipStore = getMembershipStore();
     GetNamenodeRegistrationsResponse response =
-        this.membershipInterface.getNamenodeRegistrations(request);
+        membershipStore.getNamenodeRegistrations(request);
 
     List<MembershipState> memberships = response.getNamenodeMemberships();
     if (!addExpired || !addUnavailable) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/router/Router.java

@@ -81,6 +81,10 @@ public class Router extends CompositeService {
   private RouterRpcServer rpcServer;
   private InetSocketAddress rpcAddress;
 
+  /** RPC interface for the admin. */
+  private RouterAdminServer adminServer;
+  private InetSocketAddress adminAddress;
+
   /** Interface with the State Store. */
   private StateStoreService stateStore;
 
@@ -116,6 +120,14 @@ public class Router extends CompositeService {
   protected void serviceInit(Configuration configuration) throws Exception {
     this.conf = configuration;
 
+    if (conf.getBoolean(
+        DFSConfigKeys.DFS_ROUTER_STORE_ENABLE,
+        DFSConfigKeys.DFS_ROUTER_STORE_ENABLE_DEFAULT)) {
+      // Service that maintains the State Store connection
+      this.stateStore = new StateStoreService();
+      addService(this.stateStore);
+    }
+
     // Resolver to track active NNs
     this.namenodeResolver = newActiveNamenodeResolver(
         this.conf, this.stateStore);
@@ -138,6 +150,14 @@ public class Router extends CompositeService {
       this.setRpcServerAddress(rpcServer.getRpcAddress());
     }
 
+    if (conf.getBoolean(
+        DFSConfigKeys.DFS_ROUTER_ADMIN_ENABLE,
+        DFSConfigKeys.DFS_ROUTER_ADMIN_ENABLE_DEFAULT)) {
+      // Create admin server
+      this.adminServer = createAdminServer();
+      addService(this.adminServer);
+    }
+
     if (conf.getBoolean(
         DFSConfigKeys.DFS_ROUTER_HEARTBEAT_ENABLE,
         DFSConfigKeys.DFS_ROUTER_HEARTBEAT_ENABLE_DEFAULT)) {
@@ -263,6 +283,38 @@ public class Router extends CompositeService {
     return this.rpcAddress;
   }
 
+  /////////////////////////////////////////////////////////
+  // Admin server
+  /////////////////////////////////////////////////////////
+
+  /**
+   * Create a new router admin server to handle the router admin interface.
+   *
+   * @return RouterAdminServer
+   * @throws IOException If the admin server was not successfully started.
+   */
+  protected RouterAdminServer createAdminServer() throws IOException {
+    return new RouterAdminServer(this.conf, this);
+  }
+
+  /**
+   * Set the current Admin socket for the router.
+   *
+   * @param adminAddress Admin RPC address.
+   */
+  protected void setAdminServerAddress(InetSocketAddress address) {
+    this.adminAddress = address;
+  }
+
+  /**
+   * Get the current Admin socket address for the router.
+   *
+   * @return InetSocketAddress Admin address.
+   */
+  public InetSocketAddress getAdminServerAddress() {
+    return adminAddress;
+  }
+
   /////////////////////////////////////////////////////////
   // Namenode heartbeat monitors
   /////////////////////////////////////////////////////////

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterAdminServer.java

@@ -0,0 +1,183 @@
+/**
+ * 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.hdfs.server.federation.router;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.protocol.proto.RouterProtocolProtos.RouterAdminProtocolService;
+import org.apache.hadoop.hdfs.protocolPB.RouterAdminProtocolPB;
+import org.apache.hadoop.hdfs.protocolPB.RouterAdminProtocolServerSideTranslatorPB;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.store.MountTableStore;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryResponse;
+import org.apache.hadoop.ipc.ProtobufRpcEngine;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ipc.RPC.Server;
+import org.apache.hadoop.service.AbstractService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.protobuf.BlockingService;
+
+/**
+ * This class is responsible for handling all of the Admin calls to the HDFS
+ * router. It is created, started, and stopped by {@link Router}.
+ */
+public class RouterAdminServer extends AbstractService
+    implements MountTableManager {
+
+  private static final Logger LOG =
+      LoggerFactory.getLogger(RouterAdminServer.class);
+
+  private Configuration conf;
+
+  private final Router router;
+
+  private MountTableStore mountTableStore;
+
+  /** The Admin server that listens to requests from clients. */
+  private final Server adminServer;
+  private final InetSocketAddress adminAddress;
+
+  public RouterAdminServer(Configuration conf, Router router)
+      throws IOException {
+    super(RouterAdminServer.class.getName());
+
+    this.conf = conf;
+    this.router = router;
+
+    int handlerCount = this.conf.getInt(
+        DFSConfigKeys.DFS_ROUTER_ADMIN_HANDLER_COUNT_KEY,
+        DFSConfigKeys.DFS_ROUTER_ADMIN_HANDLER_COUNT_DEFAULT);
+
+    RPC.setProtocolEngine(this.conf, RouterAdminProtocolPB.class,
+        ProtobufRpcEngine.class);
+
+    RouterAdminProtocolServerSideTranslatorPB routerAdminProtocolTranslator =
+        new RouterAdminProtocolServerSideTranslatorPB(this);
+    BlockingService clientNNPbService = RouterAdminProtocolService.
+        newReflectiveBlockingService(routerAdminProtocolTranslator);
+
+    InetSocketAddress confRpcAddress = conf.getSocketAddr(
+        DFSConfigKeys.DFS_ROUTER_ADMIN_BIND_HOST_KEY,
+        DFSConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_KEY,
+        DFSConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_DEFAULT,
+        DFSConfigKeys.DFS_ROUTER_ADMIN_PORT_DEFAULT);
+
+    String bindHost = conf.get(
+        DFSConfigKeys.DFS_ROUTER_ADMIN_BIND_HOST_KEY,
+        confRpcAddress.getHostName());
+    LOG.info("Admin server binding to {}:{}",
+        bindHost, confRpcAddress.getPort());
+
+    this.adminServer = new RPC.Builder(this.conf)
+        .setProtocol(RouterAdminProtocolPB.class)
+        .setInstance(clientNNPbService)
+        .setBindAddress(bindHost)
+        .setPort(confRpcAddress.getPort())
+        .setNumHandlers(handlerCount)
+        .setVerbose(false)
+        .build();
+
+    // The RPC-server port can be ephemeral... ensure we have the correct info
+    InetSocketAddress listenAddress = this.adminServer.getListenerAddress();
+    this.adminAddress = new InetSocketAddress(
+        confRpcAddress.getHostName(), listenAddress.getPort());
+    router.setAdminServerAddress(this.adminAddress);
+  }
+
+  /** Allow access to the client RPC server for testing. */
+  @VisibleForTesting
+  Server getAdminServer() {
+    return this.adminServer;
+  }
+
+  private MountTableStore getMountTableStore() throws IOException {
+    if (this.mountTableStore == null) {
+      this.mountTableStore = router.getStateStore().getRegisteredRecordStore(
+          MountTableStore.class);
+      if (this.mountTableStore == null) {
+        throw new IOException("Mount table state store is not available.");
+      }
+    }
+    return this.mountTableStore;
+  }
+
+  /**
+   * Get the RPC address of the admin service.
+   * @return Administration service RPC address.
+   */
+  public InetSocketAddress getRpcAddress() {
+    return this.adminAddress;
+  }
+
+  @Override
+  protected void serviceInit(Configuration configuration) throws Exception {
+    this.conf = configuration;
+    super.serviceInit(conf);
+  }
+
+  @Override
+  protected void serviceStart() throws Exception {
+    this.adminServer.start();
+    super.serviceStart();
+  }
+
+  @Override
+  protected void serviceStop() throws Exception {
+    if (this.adminServer != null) {
+      this.adminServer.stop();
+    }
+    super.serviceStop();
+  }
+
+  @Override
+  public AddMountTableEntryResponse addMountTableEntry(
+      AddMountTableEntryRequest request) throws IOException {
+    return getMountTableStore().addMountTableEntry(request);
+  }
+
+  @Override
+  public UpdateMountTableEntryResponse updateMountTableEntry(
+      UpdateMountTableEntryRequest request) throws IOException {
+    return getMountTableStore().updateMountTableEntry(request);
+  }
+
+  @Override
+  public RemoveMountTableEntryResponse removeMountTableEntry(
+      RemoveMountTableEntryRequest request) throws IOException {
+    return getMountTableStore().removeMountTableEntry(request);
+  }
+
+  @Override
+  public GetMountTableEntriesResponse getMountTableEntries(
+      GetMountTableEntriesRequest request) throws IOException {
+    return getMountTableStore().getMountTableEntries(request);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClient.java

@@ -0,0 +1,76 @@
+/**
+ * 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.hdfs.server.federation.router;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.protocolPB.RouterAdminProtocolPB;
+import org.apache.hadoop.hdfs.protocolPB.RouterAdminProtocolTranslatorPB;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.ipc.ProtobufRpcEngine;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.security.UserGroupInformation;
+
+/**
+ * Client to connect to the {@link Router} via the admin protocol.
+ */
+@Private
+public class RouterClient implements Closeable {
+
+  private final RouterAdminProtocolTranslatorPB proxy;
+  private final UserGroupInformation ugi;
+
+  private static RouterAdminProtocolTranslatorPB createRouterProxy(
+      InetSocketAddress address, Configuration conf, UserGroupInformation ugi)
+          throws IOException {
+
+    RPC.setProtocolEngine(
+        conf, RouterAdminProtocolPB.class, ProtobufRpcEngine.class);
+
+    AtomicBoolean fallbackToSimpleAuth = new AtomicBoolean(false);
+    final long version = RPC.getProtocolVersion(RouterAdminProtocolPB.class);
+    RouterAdminProtocolPB proxy = RPC.getProtocolProxy(
+        RouterAdminProtocolPB.class, version, address, ugi, conf,
+        NetUtils.getDefaultSocketFactory(conf),
+        RPC.getRpcTimeout(conf), null,
+        fallbackToSimpleAuth).getProxy();
+
+    return new RouterAdminProtocolTranslatorPB(proxy);
+  }
+
+  public RouterClient(InetSocketAddress address, Configuration conf)
+      throws IOException {
+    this.ugi = UserGroupInformation.getCurrentUser();
+    this.proxy = createRouterProxy(address, conf, ugi);
+  }
+
+  public MountTableManager getMountTableManager() {
+    return proxy;
+  }
+
+  @Override
+  public synchronized void close() throws IOException {
+    RPC.stopProxy(proxy);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/federation/RouterAdmin.java

@@ -0,0 +1,341 @@
+/**
+ * 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.hdfs.tools.federation;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.conf.Configured;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.resolver.RemoteLocation;
+import org.apache.hadoop.hdfs.server.federation.resolver.order.DestinationOrder;
+import org.apache.hadoop.hdfs.server.federation.router.RouterClient;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ipc.RemoteException;
+import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.util.Tool;
+import org.apache.hadoop.util.ToolRunner;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class provides some Federation administrative access shell commands.
+ */
+@Private
+public class RouterAdmin extends Configured implements Tool {
+
+  private static final Logger LOG = LoggerFactory.getLogger(RouterAdmin.class);
+
+  private RouterClient client;
+
+  public static void main(String[] argv) throws Exception {
+    Configuration conf = new HdfsConfiguration();
+    RouterAdmin admin = new RouterAdmin(conf);
+
+    int res = ToolRunner.run(admin, argv);
+    System.exit(res);
+  }
+
+  public RouterAdmin(Configuration conf) {
+    super(conf);
+  }
+
+  /**
+   * Print the usage message.
+   */
+  public void printUsage() {
+    String usage = "Federation Admin Tools:\n"
+        + "\t[-add <source> <nameservice> <destination> "
+        + "[-readonly] [-order HASH|LOCAL|RANDOM|HASH_ALL]]\n"
+        + "\t[-rm <source>]\n"
+        + "\t[-ls <path>]\n";
+    System.out.println(usage);
+  }
+
+  @Override
+  public int run(String[] argv) throws Exception {
+    if (argv.length < 1) {
+      System.err.println("Not enough parameters specificed");
+      printUsage();
+      return -1;
+    }
+
+    int exitCode = -1;
+    int i = 0;
+    String cmd = argv[i++];
+
+    // Verify that we have enough command line parameters
+    if ("-add".equals(cmd)) {
+      if (argv.length < 4) {
+        System.err.println("Not enough parameters specificed for cmd " + cmd);
+        printUsage();
+        return exitCode;
+      }
+    } else if ("-rm".equalsIgnoreCase(cmd)) {
+      if (argv.length < 2) {
+        System.err.println("Not enough parameters specificed for cmd " + cmd);
+        printUsage();
+        return exitCode;
+      }
+    }
+
+    // Initialize RouterClient
+    try {
+      String address = getConf().getTrimmed(
+          DFSConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_KEY,
+          DFSConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_DEFAULT);
+      InetSocketAddress routerSocket = NetUtils.createSocketAddr(address);
+      client = new RouterClient(routerSocket, getConf());
+    } catch (RPC.VersionMismatch v) {
+      System.err.println(
+          "Version mismatch between client and server... command aborted");
+      return exitCode;
+    } catch (IOException e) {
+      System.err.println("Bad connection to Router... command aborted");
+      return exitCode;
+    }
+
+    Exception debugException = null;
+    exitCode = 0;
+    try {
+      if ("-add".equals(cmd)) {
+        if (addMount(argv, i)) {
+          System.err.println("Successfuly added mount point " + argv[i]);
+        }
+      } else if ("-rm".equals(cmd)) {
+        if (removeMount(argv[i])) {
+          System.err.println("Successfully removed mount point " + argv[i]);
+        }
+      } else if ("-ls".equals(cmd)) {
+        if (argv.length > 1) {
+          listMounts(argv[i]);
+        } else {
+          listMounts("/");
+        }
+      } else {
+        printUsage();
+        return exitCode;
+      }
+    } catch (IllegalArgumentException arge) {
+      debugException = arge;
+      exitCode = -1;
+      System.err.println(cmd.substring(1) + ": " + arge.getLocalizedMessage());
+      printUsage();
+    } catch (RemoteException e) {
+      // This is a error returned by the server.
+      // Print out the first line of the error message, ignore the stack trace.
+      exitCode = -1;
+      debugException = e;
+      try {
+        String[] content;
+        content = e.getLocalizedMessage().split("\n");
+        System.err.println(cmd.substring(1) + ": " + content[0]);
+        e.printStackTrace();
+      } catch (Exception ex) {
+        System.err.println(cmd.substring(1) + ": " + ex.getLocalizedMessage());
+        e.printStackTrace();
+        debugException = ex;
+      }
+    } catch (Exception e) {
+      exitCode = -1;
+      debugException = e;
+      System.err.println(cmd.substring(1) + ": " + e.getLocalizedMessage());
+      e.printStackTrace();
+    }
+    if (debugException != null) {
+      LOG.debug("Exception encountered", debugException);
+    }
+    return exitCode;
+  }
+
+  /**
+   * Add a mount table entry or update if it exists.
+   *
+   * @param parameters Parameters for the mount point.
+   * @param i Index in the parameters.
+   */
+  public boolean addMount(String[] parameters, int i) throws IOException {
+    // Mandatory parameters
+    String mount = parameters[i++];
+    String[] nss = parameters[i++].split(",");
+    String dest = parameters[i++];
+
+    // Optional parameters
+    boolean readOnly = false;
+    DestinationOrder order = DestinationOrder.HASH;
+    while (i < parameters.length) {
+      if (parameters[i].equals("-readonly")) {
+        readOnly = true;
+      } else if (parameters[i].equals("-order")) {
+        i++;
+        try {
+          order = DestinationOrder.valueOf(parameters[i]);
+        } catch(Exception e) {
+          System.err.println("Cannot parse order: " + parameters[i]);
+        }
+      }
+      i++;
+    }
+
+    return addMount(mount, nss, dest, readOnly, order);
+  }
+
+  /**
+   * Add a mount table entry or update if it exists.
+   *
+   * @param mount Mount point.
+   * @param nss Namespaces where this is mounted to.
+   * @param dest Destination path.
+   * @param readonly If the mount point is read only.
+   * @param order Order of the destination locations.
+   * @return If the mount point was added.
+   * @throws IOException Error adding the mount point.
+   */
+  public boolean addMount(String mount, String[] nss, String dest,
+      boolean readonly, DestinationOrder order) throws IOException {
+    // Get the existing entry
+    MountTableManager mountTable = client.getMountTableManager();
+    GetMountTableEntriesRequest getRequest =
+        GetMountTableEntriesRequest.newInstance(mount);
+    GetMountTableEntriesResponse getResponse =
+        mountTable.getMountTableEntries(getRequest);
+    List<MountTable> results = getResponse.getEntries();
+    MountTable existingEntry = null;
+    for (MountTable result : results) {
+      if (mount.equals(result.getSourcePath())) {
+        existingEntry = result;
+      }
+    }
+
+    if (existingEntry == null) {
+      // Create and add the entry if it doesn't exist
+      Map<String, String> destMap = new LinkedHashMap<>();
+      for (String ns : nss) {
+        destMap.put(ns, dest);
+      }
+      MountTable newEntry = MountTable.newInstance(mount, destMap);
+      if (readonly) {
+        newEntry.setReadOnly(true);
+      }
+      if (order != null) {
+        newEntry.setDestOrder(order);
+      }
+      AddMountTableEntryRequest request =
+          AddMountTableEntryRequest.newInstance(newEntry);
+      AddMountTableEntryResponse addResponse =
+          mountTable.addMountTableEntry(request);
+      boolean added = addResponse.getStatus();
+      if (!added) {
+        System.err.println("Cannot add mount point " + mount);
+      }
+      return added;
+    } else {
+      // Update the existing entry if it exists
+      for (String nsId : nss) {
+        if (!existingEntry.addDestination(nsId, dest)) {
+          System.err.println("Cannot add destination at " + nsId + " " + dest);
+        }
+      }
+      if (readonly) {
+        existingEntry.setReadOnly(true);
+      }
+      if (order != null) {
+        existingEntry.setDestOrder(order);
+      }
+      UpdateMountTableEntryRequest updateRequest =
+          UpdateMountTableEntryRequest.newInstance(existingEntry);
+      UpdateMountTableEntryResponse updateResponse =
+          mountTable.updateMountTableEntry(updateRequest);
+      boolean updated = updateResponse.getStatus();
+      if (!updated) {
+        System.err.println("Cannot update mount point " + mount);
+      }
+      return updated;
+    }
+  }
+
+  /**
+   * Remove mount point.
+   *
+   * @param path Path to remove.
+   * @throws IOException If it cannot be removed.
+   */
+  public boolean removeMount(String path) throws IOException {
+    MountTableManager mountTable = client.getMountTableManager();
+    RemoveMountTableEntryRequest request =
+        RemoveMountTableEntryRequest.newInstance(path);
+    RemoveMountTableEntryResponse response =
+        mountTable.removeMountTableEntry(request);
+    boolean removed = response.getStatus();
+    if (!removed) {
+      System.out.println("Cannot remove mount point " + path);
+    }
+    return removed;
+  }
+
+  /**
+   * List mount points.
+   *
+   * @param path Path to list.
+   * @throws IOException If it cannot be listed.
+   */
+  public void listMounts(String path) throws IOException {
+    MountTableManager mountTable = client.getMountTableManager();
+    GetMountTableEntriesRequest request =
+        GetMountTableEntriesRequest.newInstance(path);
+    GetMountTableEntriesResponse response =
+        mountTable.getMountTableEntries(request);
+    List<MountTable> entries = response.getEntries();
+    printMounts(entries);
+  }
+
+  private static void printMounts(List<MountTable> entries) {
+    System.out.println("Mount Table Entries:");
+    System.out.println(String.format(
+        "%-25s %-25s",
+        "Source", "Destinations"));
+    for (MountTable entry : entries) {
+      StringBuilder destBuilder = new StringBuilder();
+      for (RemoteLocation location : entry.getDestinations()) {
+        if (destBuilder.length() > 0) {
+          destBuilder.append(",");
+        }
+        destBuilder.append(String.format("%s->%s", location.getNameserviceId(),
+            location.getDest()));
+      }
+      System.out.println(String.format("%-25s %-25s", entry.getSourcePath(),
+          destBuilder.toString()));
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/federation/package-info.java

@@ -0,0 +1,28 @@
+/**
+ * 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.
+ */
+
+/**
+ * It includes the tools to manage the Router-based federation. Includes the
+ * utilities to add and remove mount table entries.
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+package org.apache.hadoop.hdfs.tools.federation;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/RouterProtocol.proto

@@ -0,0 +1,47 @@
+/**
+ * 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.
+ */
+
+option java_package = "org.apache.hadoop.hdfs.protocol.proto";
+option java_outer_classname = "RouterProtocolProtos";
+option java_generic_services = true;
+option java_generate_equals_and_hash = true;
+package hadoop.hdfs.router;
+
+import "FederationProtocol.proto";
+
+service RouterAdminProtocolService {
+  /**
+   * Add a mount table entry.
+   */
+  rpc addMountTableEntry(AddMountTableEntryRequestProto) returns(AddMountTableEntryResponseProto);
+
+  /**
+   * Update an existing mount table entry without copying files.
+   */
+  rpc updateMountTableEntry(UpdateMountTableEntryRequestProto) returns(UpdateMountTableEntryResponseProto);
+
+  /**
+   * Remove a mount table entry.
+   */
+  rpc removeMountTableEntry(RemoveMountTableEntryRequestProto) returns(RemoveMountTableEntryResponseProto);
+
+  /**
+   * Get matching mount entries
+   */
+  rpc getMountTableEntries(GetMountTableEntriesRequestProto) returns(GetMountTableEntriesResponseProto);
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -4745,6 +4745,44 @@
     </description>
   </property>
 
+    <property>
+    <name>dfs.federation.router.admin.enable</name>
+    <value>true</value>
+    <description>
+      If the RPC admin service to handle client requests in the router is
+      enabled.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.federation.router.admin-address</name>
+    <value>0.0.0.0:8111</value>
+    <description>
+      RPC address that handles the admin requests.
+      The value of this property will take the form of router-host1:rpc-port.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.federation.router.admin-bind-host</name>
+    <value></value>
+    <description>
+      The actual address the RPC admin server will bind to. If this optional
+      address is set, it overrides only the hostname portion of
+      dfs.federation.router.admin-address. This is useful for making the name
+      node listen on all interfaces by setting it to 0.0.0.0.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.federation.router.admin.handler.count</name>
+    <value>1</value>
+    <description>
+      The number of server threads for the router to handle RPC requests from
+      admin.
+    </description>
+  </property>
+
   <property>
     <name>dfs.federation.router.file.resolver.client.class</name>
     <value>org.apache.hadoop.hdfs.server.federation.MockResolver</value>
@@ -4761,6 +4799,14 @@
     </description>
   </property>
 
+  <property>
+    <name>dfs.federation.router.store.enable</name>
+    <value>true</value>
+    <description>
+      If the Router connects to the State Store.
+    </description>
+  </property>
+
   <property>
     <name>dfs.federation.router.store.serializer</name>
     <value>org.apache.hadoop.hdfs.server.federation.store.driver.impl.StateStoreSerializerPBImpl</value>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/RouterConfigBuilder.java

@@ -28,8 +28,10 @@ public class RouterConfigBuilder {
   private Configuration conf;
 
   private boolean enableRpcServer = false;
+  private boolean enableAdminServer = false;
   private boolean enableHeartbeat = false;
   private boolean enableLocalHeartbeat = false;
+  private boolean enableStateStore = false;
 
   public RouterConfigBuilder(Configuration configuration) {
     this.conf = configuration;
@@ -41,8 +43,10 @@ public class RouterConfigBuilder {
 
   public RouterConfigBuilder all() {
     this.enableRpcServer = true;
+    this.enableAdminServer = true;
     this.enableHeartbeat = true;
     this.enableLocalHeartbeat = true;
+    this.enableStateStore = true;
     return this;
   }
 
@@ -56,21 +60,43 @@ public class RouterConfigBuilder {
     return this;
   }
 
+  public RouterConfigBuilder admin(boolean enable) {
+    this.enableAdminServer = enable;
+    return this;
+  }
+
   public RouterConfigBuilder heartbeat(boolean enable) {
     this.enableHeartbeat = enable;
     return this;
   }
 
+  public RouterConfigBuilder stateStore(boolean enable) {
+    this.enableStateStore = enable;
+    return this;
+  }
+
   public RouterConfigBuilder rpc() {
     return this.rpc(true);
   }
 
+  public RouterConfigBuilder admin() {
+    return this.admin(true);
+  }
+
   public RouterConfigBuilder heartbeat() {
     return this.heartbeat(true);
   }
 
+  public RouterConfigBuilder stateStore() {
+    return this.stateStore(true);
+  }
+
   public Configuration build() {
+    conf.setBoolean(DFSConfigKeys.DFS_ROUTER_STORE_ENABLE,
+        this.enableStateStore);
     conf.setBoolean(DFSConfigKeys.DFS_ROUTER_RPC_ENABLE, this.enableRpcServer);
+    conf.setBoolean(DFSConfigKeys.DFS_ROUTER_ADMIN_ENABLE,
+        this.enableAdminServer);
     conf.setBoolean(DFSConfigKeys.DFS_ROUTER_HEARTBEAT_ENABLE,
         this.enableHeartbeat);
     conf.setBoolean(DFSConfigKeys.DFS_ROUTER_MONITOR_LOCAL_NAMENODE,

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/RouterDFSCluster.java

@@ -25,8 +25,12 @@ import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RPC_ADDRESS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RPC_BIND_HOST_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMESERVICES;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMESERVICE_ID;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_ADMIN_BIND_HOST_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_CACHE_TIME_TO_LIVE_MS;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_DEFAULT_NAMESERVICE;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_HANDLER_COUNT_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_HEARTBEAT_INTERVAL_MS;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_RPC_ADDRESS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_RPC_BIND_HOST_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.FEDERATION_FILE_RESOLVER_CLIENT_CLASS;
@@ -46,6 +50,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map.Entry;
 import java.util.Random;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileContext;
@@ -67,6 +72,7 @@ import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamenodeServi
 import org.apache.hadoop.hdfs.server.federation.resolver.FileSubclusterResolver;
 import org.apache.hadoop.hdfs.server.federation.resolver.NamenodeStatusReport;
 import org.apache.hadoop.hdfs.server.federation.router.Router;
+import org.apache.hadoop.hdfs.server.federation.router.RouterClient;
 import org.apache.hadoop.hdfs.server.namenode.FSImage;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
@@ -101,6 +107,15 @@ public class RouterDFSCluster {
   /** Mini cluster. */
   private MiniDFSCluster cluster;
 
+  protected static final long DEFAULT_HEARTBEAT_INTERVAL_MS =
+      TimeUnit.SECONDS.toMillis(5);
+  protected static final long DEFAULT_CACHE_INTERVAL_MS =
+      TimeUnit.SECONDS.toMillis(5);
+  /** Heartbeat interval in milliseconds. */
+  private long heartbeatInterval;
+  /** Cache flush interval in milliseconds. */
+  private long cacheFlushInterval;
+
   /** Router configuration overrides. */
   private Configuration routerOverrides;
   /** Namenode configuration overrides. */
@@ -118,6 +133,7 @@ public class RouterDFSCluster {
     private int rpcPort;
     private DFSClient client;
     private Configuration conf;
+    private RouterClient adminClient;
     private URI fileSystemUri;
 
     public RouterContext(Configuration conf, String nsId, String nnId)
@@ -183,6 +199,15 @@ public class RouterDFSCluster {
       });
     }
 
+    public RouterClient getAdminClient() throws IOException {
+      if (adminClient == null) {
+        InetSocketAddress routerSocket = router.getAdminServerAddress();
+        LOG.info("Connecting to router admin at {}", routerSocket);
+        adminClient = new RouterClient(routerSocket, conf);
+      }
+      return adminClient;
+    }
+
     public DFSClient getClient() throws IOException, URISyntaxException {
       if (client == null) {
         LOG.info("Connecting to router at {}", fileSystemUri);
@@ -304,13 +329,22 @@ public class RouterDFSCluster {
     }
   }
 
-  public RouterDFSCluster(boolean ha, int numNameservices, int numNamenodes) {
+  public RouterDFSCluster(boolean ha, int numNameservices, int numNamenodes,
+      long heartbeatInterval, long cacheFlushInterval) {
     this.highAvailability = ha;
+    this.heartbeatInterval = heartbeatInterval;
+    this.cacheFlushInterval = cacheFlushInterval;
     configureNameservices(numNameservices, numNamenodes);
   }
 
   public RouterDFSCluster(boolean ha, int numNameservices) {
-    this(ha, numNameservices, 2);
+    this(ha, numNameservices, 2,
+        DEFAULT_HEARTBEAT_INTERVAL_MS, DEFAULT_CACHE_INTERVAL_MS);
+  }
+
+  public RouterDFSCluster(boolean ha, int numNameservices, int numNamnodes) {
+    this(ha, numNameservices, numNamnodes,
+        DEFAULT_HEARTBEAT_INTERVAL_MS, DEFAULT_CACHE_INTERVAL_MS);
   }
 
   /**
@@ -404,7 +438,12 @@ public class RouterDFSCluster {
     conf.set(DFS_ROUTER_RPC_ADDRESS_KEY, "127.0.0.1:0");
     conf.set(DFS_ROUTER_RPC_BIND_HOST_KEY, "0.0.0.0");
 
+    conf.set(DFS_ROUTER_ADMIN_ADDRESS_KEY, "127.0.0.1:0");
+    conf.set(DFS_ROUTER_ADMIN_BIND_HOST_KEY, "0.0.0.0");
+
     conf.set(DFS_ROUTER_DEFAULT_NAMESERVICE, nameservices.get(0));
+    conf.setLong(DFS_ROUTER_HEARTBEAT_INTERVAL_MS, heartbeatInterval);
+    conf.setLong(DFS_ROUTER_CACHE_TIME_TO_LIVE_MS, cacheFlushInterval);
 
     // Use mock resolver classes
     conf.setClass(FEDERATION_NAMENODE_RESOLVER_CLIENT_CLASS,

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/StateStoreDFSCluster.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.hdfs.server.federation;
+
+import static org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils.createMockRegistrationForNamenode;
+import static org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils.getStateStoreConfiguration;
+import static org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils.synchronizeRecords;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamenodeServiceState;
+import org.apache.hadoop.hdfs.server.federation.resolver.FileSubclusterResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.MembershipNamenodeResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableResolver;
+import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
+import org.apache.hadoop.hdfs.server.federation.store.records.MembershipState;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+
+/**
+ * Test utility to mimic a federated HDFS cluster with a router and a state
+ * store.
+ */
+public class StateStoreDFSCluster extends RouterDFSCluster {
+
+  private static final Class<?> DEFAULT_FILE_RESOLVER =
+      MountTableResolver.class;
+  private static final Class<?> DEFAULT_NAMENODE_RESOLVER =
+      MembershipNamenodeResolver.class;
+
+  public StateStoreDFSCluster(boolean ha, int numNameservices, int numNamenodes,
+      long heartbeatInterval, long cacheFlushInterval)
+          throws IOException, InterruptedException {
+    this(ha, numNameservices, numNamenodes, heartbeatInterval,
+        cacheFlushInterval, DEFAULT_FILE_RESOLVER);
+  }
+
+  public StateStoreDFSCluster(boolean ha, int numNameservices, int numNamenodes,
+      long heartbeatInterval, long cacheFlushInterval, Class<?> fileResolver)
+          throws IOException, InterruptedException {
+    super(ha, numNameservices, numNamenodes, heartbeatInterval,
+        cacheFlushInterval);
+
+    // Attach state store and resolvers to router
+    Configuration stateStoreConfig = getStateStoreConfiguration();
+    // Use state store backed resolvers
+    stateStoreConfig.setClass(
+        DFSConfigKeys.FEDERATION_NAMENODE_RESOLVER_CLIENT_CLASS,
+        DEFAULT_NAMENODE_RESOLVER, ActiveNamenodeResolver.class);
+    stateStoreConfig.setClass(
+        DFSConfigKeys.FEDERATION_FILE_RESOLVER_CLIENT_CLASS,
+        fileResolver, FileSubclusterResolver.class);
+    this.addRouterOverrides(stateStoreConfig);
+  }
+
+  public StateStoreDFSCluster(boolean ha, int numNameservices,
+      Class<?> fileResolver) throws IOException, InterruptedException {
+    this(ha, numNameservices, 2,
+        DEFAULT_HEARTBEAT_INTERVAL_MS, DEFAULT_CACHE_INTERVAL_MS, fileResolver);
+  }
+
+  public StateStoreDFSCluster(boolean ha, int numNameservices)
+      throws IOException, InterruptedException {
+    this(ha, numNameservices, 2,
+        DEFAULT_HEARTBEAT_INTERVAL_MS, DEFAULT_CACHE_INTERVAL_MS);
+  }
+
+  public StateStoreDFSCluster(boolean ha, int numNameservices,
+      int numNamnodes) throws IOException, InterruptedException {
+    this(ha, numNameservices, numNamnodes,
+        DEFAULT_HEARTBEAT_INTERVAL_MS, DEFAULT_CACHE_INTERVAL_MS);
+  }
+
+  /////////////////////////////////////////////////////////////////////////////
+  // State Store Test Fixtures
+  /////////////////////////////////////////////////////////////////////////////
+
+  /**
+   * Adds test fixtures for NN registation for each NN nameservice -> NS
+   * namenode -> NN rpcAddress -> 0.0.0.0:0 webAddress -> 0.0.0.0:0 state ->
+   * STANDBY safeMode -> false blockPool -> test.
+   *
+   * @param stateStore State Store.
+   * @throws IOException If it cannot register.
+   */
+  public void createTestRegistration(StateStoreService stateStore)
+      throws IOException {
+    List<MembershipState> entries = new ArrayList<MembershipState>();
+    for (NamenodeContext nn : this.getNamenodes()) {
+      MembershipState entry = createMockRegistrationForNamenode(
+          nn.getNameserviceId(), nn.getNamenodeId(),
+          FederationNamenodeServiceState.STANDBY);
+      entries.add(entry);
+    }
+    synchronizeRecords(
+        stateStore, entries, MembershipState.class);
+  }
+
+  public void createTestMountTable(StateStoreService stateStore)
+      throws IOException {
+    List<MountTable> mounts = generateMockMountTable();
+    synchronizeRecords(stateStore, mounts, MountTable.class);
+    stateStore.refreshCaches();
+  }
+
+  public List<MountTable> generateMockMountTable() throws IOException {
+    // create table entries
+    List<MountTable> entries = new ArrayList<>();
+    for (String ns : this.getNameservices()) {
+      Map<String, String> destMap = new HashMap<>();
+      destMap.put(ns, getNamenodePathForNS(ns));
+
+      // Direct path
+      String fedPath = getFederatedPathForNS(ns);
+      MountTable entry = MountTable.newInstance(fedPath, destMap);
+      entries.add(entry);
+    }
+
+    // Root path goes to nameservice 1
+    Map<String, String> destMap = new HashMap<>();
+    String ns0 = this.getNameservices().get(0);
+    destMap.put(ns0, "/");
+    MountTable entry = MountTable.newInstance("/", destMap);
+    entries.add(entry);
+    return entries;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterAdmin.java

@@ -0,0 +1,261 @@
+/**
+ * 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.hdfs.server.federation.router;
+
+import static org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils.synchronizeRecords;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.federation.RouterDFSCluster.RouterContext;
+import org.apache.hadoop.hdfs.server.federation.StateStoreDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.resolver.RemoteLocation;
+import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
+import org.apache.hadoop.hdfs.server.federation.store.impl.MountTableStoreImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+import org.apache.hadoop.util.Time;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/**
+ * The administrator interface of the {@link Router} implemented by
+ * {@link RouterAdminServer}.
+ */
+public class TestRouterAdmin {
+
+  private static StateStoreDFSCluster cluster;
+  private static RouterContext routerContext;
+  public static final String RPC_BEAN =
+      "Hadoop:service=Router,name=FederationRPC";
+  private static List<MountTable> mockMountTable;
+  private static StateStoreService stateStore;
+
+  @BeforeClass
+  public static void globalSetUp() throws Exception {
+    cluster = new StateStoreDFSCluster(false, 1);
+    // Build and start a router with State Store + admin + RPC
+    Configuration conf = new RouterConfigBuilder()
+        .stateStore()
+        .admin()
+        .rpc()
+        .build();
+    cluster.addRouterOverrides(conf);
+    cluster.startRouters();
+    routerContext = cluster.getRandomRouter();
+    mockMountTable = cluster.generateMockMountTable();
+    Router router = routerContext.getRouter();
+    stateStore = router.getStateStore();
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    cluster.stopRouter(routerContext);
+  }
+
+  @Before
+  public void testSetup() throws Exception {
+    assertTrue(
+        synchronizeRecords(stateStore, mockMountTable, MountTable.class));
+  }
+
+  @Test
+  public void testAddMountTable() throws IOException {
+    MountTable newEntry = MountTable.newInstance(
+        "/testpath", Collections.singletonMap("ns0", "/testdir"),
+        Time.now(), Time.now());
+
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+
+    // Existing mount table size
+    List<MountTable> records = getMountTableEntries(mountTable);
+    assertEquals(records.size(), mockMountTable.size());
+
+    // Add
+    AddMountTableEntryRequest addRequest =
+        AddMountTableEntryRequest.newInstance(newEntry);
+    AddMountTableEntryResponse addResponse =
+        mountTable.addMountTableEntry(addRequest);
+    assertTrue(addResponse.getStatus());
+
+    // New mount table size
+    List<MountTable> records2 = getMountTableEntries(mountTable);
+    assertEquals(records2.size(), mockMountTable.size() + 1);
+  }
+
+  @Test
+  public void testAddDuplicateMountTable() throws IOException {
+    MountTable newEntry = MountTable.newInstance("/testpath",
+        Collections.singletonMap("ns0", "/testdir"), Time.now(), Time.now());
+
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+
+    // Existing mount table size
+    List<MountTable> entries1 = getMountTableEntries(mountTable);
+    assertEquals(entries1.size(), mockMountTable.size());
+
+    // Add
+    AddMountTableEntryRequest addRequest =
+        AddMountTableEntryRequest.newInstance(newEntry);
+    AddMountTableEntryResponse addResponse =
+        mountTable.addMountTableEntry(addRequest);
+    assertTrue(addResponse.getStatus());
+
+    // New mount table size
+    List<MountTable> entries2 = getMountTableEntries(mountTable);
+    assertEquals(entries2.size(), mockMountTable.size() + 1);
+
+    // Add again, should fail
+    AddMountTableEntryResponse addResponse2 =
+        mountTable.addMountTableEntry(addRequest);
+    assertFalse(addResponse2.getStatus());
+  }
+
+  @Test
+  public void testRemoveMountTable() throws IOException {
+
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+
+    // Existing mount table size
+    List<MountTable> entries1 = getMountTableEntries(mountTable);
+    assertEquals(entries1.size(), mockMountTable.size());
+
+    // Remove an entry
+    RemoveMountTableEntryRequest removeRequest =
+        RemoveMountTableEntryRequest.newInstance("/");
+    mountTable.removeMountTableEntry(removeRequest);
+
+    // New mount table size
+    List<MountTable> entries2 = getMountTableEntries(mountTable);
+    assertEquals(entries2.size(), mockMountTable.size() - 1);
+  }
+
+  @Test
+  public void testEditMountTable() throws IOException {
+
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+
+    // Verify starting condition
+    MountTable entry = getMountTableEntry("/");
+    assertEquals(
+        Collections.singletonList(new RemoteLocation("ns0", "/")),
+        entry.getDestinations());
+
+    // Edit the entry for /
+    MountTable updatedEntry = MountTable.newInstance(
+        "/", Collections.singletonMap("ns1", "/"), Time.now(), Time.now());
+    UpdateMountTableEntryRequest updateRequest =
+        UpdateMountTableEntryRequest.newInstance(updatedEntry);
+    mountTable.updateMountTableEntry(updateRequest);
+
+    // Verify edited condition
+    entry = getMountTableEntry("/");
+    assertEquals(
+        Collections.singletonList(new RemoteLocation("ns1", "/")),
+        entry.getDestinations());
+  }
+
+  @Test
+  public void testGetMountTable() throws IOException {
+
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+
+    // Verify size of table
+    List<MountTable> entries = getMountTableEntries(mountTable);
+    assertEquals(mockMountTable.size(), entries.size());
+
+    // Verify all entries are present
+    int matches = 0;
+    for (MountTable e : entries) {
+      for (MountTable entry : mockMountTable) {
+        assertEquals(e.getDestinations().size(), 1);
+        assertNotNull(e.getDateCreated());
+        assertNotNull(e.getDateModified());
+        if (entry.getSourcePath().equals(e.getSourcePath())) {
+          matches++;
+        }
+      }
+    }
+    assertEquals(matches, mockMountTable.size());
+  }
+
+  @Test
+  public void testGetSingleMountTableEntry() throws IOException {
+    MountTable entry = getMountTableEntry("/ns0");
+    assertNotNull(entry);
+    assertEquals(entry.getSourcePath(), "/ns0");
+  }
+
+  /**
+   * Gets an existing mount table record in the state store.
+   *
+   * @param mount The mount point of the record to remove.
+   * @return The matching record if found, null if it is not found.
+   * @throws IOException If the state store could not be accessed.
+   */
+  private MountTable getMountTableEntry(final String mount) throws IOException {
+    // Refresh the cache
+    stateStore.loadCache(MountTableStoreImpl.class, true);
+
+    GetMountTableEntriesRequest request =
+        GetMountTableEntriesRequest.newInstance(mount);
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTable = client.getMountTableManager();
+    List<MountTable> results = getMountTableEntries(mountTable, request);
+    if (results.size() > 0) {
+      // First result is sorted to have the shortest mount string length
+      return results.get(0);
+    }
+    return null;
+  }
+
+  private List<MountTable> getMountTableEntries(MountTableManager mountTable)
+      throws IOException {
+    GetMountTableEntriesRequest request =
+        GetMountTableEntriesRequest.newInstance("/");
+    return getMountTableEntries(mountTable, request);
+  }
+
+  private List<MountTable> getMountTableEntries(MountTableManager mountTable,
+      GetMountTableEntriesRequest request) throws IOException {
+    stateStore.loadCache(MountTableStoreImpl.class, true);
+    GetMountTableEntriesResponse response =
+        mountTable.getMountTableEntries(request);
+    return response.getEntries();
+  }
+}