HDFS-12772. RBF: Federation Router State State Store internal API. Contributed by Inigo Goiri.

(cherry picked from commit 95743c672e)

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

@@ -30,6 +30,7 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
 import org.apache.hadoop.hdfs.server.federation.resolver.FileSubclusterResolver;
 import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
+import org.apache.hadoop.util.VersionInfo;
 import org.codehaus.jettison.json.JSONArray;
 import org.codehaus.jettison.json.JSONException;
 import org.codehaus.jettison.json.JSONObject;
@@ -105,6 +106,25 @@ public final class FederationUtil {
     return ret;
   }
 
+  /**
+   * Fetch the compile timestamp for this jar.
+   *
+   * @return Date compiled.
+   */
+  public static String getBuildVersion() {
+    return VersionInfo.getBuildVersion();
+  }
+
+  /**
+   * Fetch the build/compile information for this jar.
+   *
+   * @return String Compilation info.
+   */
+  public static String getCompileInfo() {
+    return VersionInfo.getDate() + " by " + VersionInfo.getUser() + " from "
+        + VersionInfo.getBranch();
+  }
+
   /**
    * Create an instance of an interface with a constructor using a context.
    *

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

@@ -0,0 +1,31 @@
+/**
+ * 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;
+
+/**
+ * States of the Router.
+ */
+public enum RouterServiceState {
+  NONE,
+  INITIALIZING,
+  SAFEMODE,
+  RUNNING,
+  STOPPING,
+  SHUTDOWN,
+  EXPIRED;
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/RouterStore.java

@@ -0,0 +1,78 @@
+/**
+ * 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.store;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+
+/**
+ * Management API for
+ * {@link org.apache.hadoop.hdfs.server.federation.store.records.RouterState
+ *  RouterState} records in the state store. Accesses the data store via the
+ * {@link org.apache.hadoop.hdfs.server.federation.store.driver.
+ * StateStoreDriver StateStoreDriver} interface. No data is cached.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public abstract class RouterStore extends CachedRecordStore<RouterState> {
+
+  public RouterStore(StateStoreDriver driver) {
+    super(RouterState.class, driver, true);
+  }
+
+  /**
+   * Fetches the current router state object.
+   *
+   * @param request Fully populated request object.
+   * @return The matching router record or null if none exists.
+   * @throws IOException Throws exception if unable to query the data store or
+   *           if more than one matching record is found.
+   */
+  public abstract GetRouterRegistrationResponse getRouterRegistration(
+      GetRouterRegistrationRequest request) throws IOException;
+
+  /**
+   * Fetches all router status objects.
+   *
+   * @param request Fully populated request object.
+   * @return List of Router records present in the data store.
+   * @throws IOException Throws exception if unable to query the data store
+   */
+  public abstract GetRouterRegistrationsResponse getRouterRegistrations(
+      GetRouterRegistrationsRequest request) throws IOException;
+
+  /**
+   * Update the state of this router in the State Store.
+   *
+   * @param request Fully populated request object.
+   * @return True if the update was successfully recorded, false otherwise.
+   * @throws IOException Throws exception if unable to query the data store
+   */
+  public abstract RouterHeartbeatResponse routerHeartbeat(
+      RouterHeartbeatRequest request) throws IOException;
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/impl/RouterStoreImpl.java

@@ -0,0 +1,93 @@
+/**
+ * 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.store.impl;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hdfs.server.federation.store.RouterStore;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.Query;
+import org.apache.hadoop.hdfs.server.federation.store.records.QueryResult;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+
+/**
+ * Implementation of the {@link RouterStore} state store API.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class RouterStoreImpl extends RouterStore {
+
+  public RouterStoreImpl(StateStoreDriver driver) {
+    super(driver);
+  }
+
+  @Override
+  public GetRouterRegistrationResponse getRouterRegistration(
+      GetRouterRegistrationRequest request) throws IOException {
+
+    final RouterState partial = RouterState.newInstance();
+    partial.setAddress(request.getRouterId());
+    final Query<RouterState> query = new Query<RouterState>(partial);
+    RouterState record = getDriver().get(getRecordClass(), query);
+    if (record != null) {
+      overrideExpiredRecord(record);
+    }
+    GetRouterRegistrationResponse response =
+        GetRouterRegistrationResponse.newInstance();
+    response.setRouter(record);
+    return response;
+  }
+
+  @Override
+  public GetRouterRegistrationsResponse getRouterRegistrations(
+      GetRouterRegistrationsRequest request) throws IOException {
+
+    // Get all values from the cache
+    QueryResult<RouterState> recordsAndTimeStamp =
+        getCachedRecordsAndTimeStamp();
+    List<RouterState> records = recordsAndTimeStamp.getRecords();
+    long timestamp = recordsAndTimeStamp.getTimestamp();
+
+    // Generate response
+    GetRouterRegistrationsResponse response =
+        GetRouterRegistrationsResponse.newInstance();
+    response.setRouters(records);
+    response.setTimestamp(timestamp);
+    return response;
+  }
+
+  @Override
+  public RouterHeartbeatResponse routerHeartbeat(RouterHeartbeatRequest request)
+      throws IOException {
+
+    RouterState record = request.getRouter();
+    boolean status = getDriver().put(record, true, false);
+    RouterHeartbeatResponse response =
+        RouterHeartbeatResponse.newInstance(status);
+    return response;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/GetRouterRegistrationRequest.java

@@ -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.
+ */
+package org.apache.hadoop.hdfs.server.federation.store.protocol;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+
+/**
+ * API request for retrieving a single router registration present in the state
+ * store.
+ */
+public abstract class GetRouterRegistrationRequest {
+
+  public static GetRouterRegistrationRequest newInstance() {
+    return StateStoreSerializer.newRecord(GetRouterRegistrationRequest.class);
+  }
+
+  public static GetRouterRegistrationRequest newInstance(String routerId) {
+    GetRouterRegistrationRequest request = newInstance();
+    request.setRouterId(routerId);
+    return request;
+  }
+
+  @Public
+  @Unstable
+  public abstract String getRouterId();
+
+  @Public
+  @Unstable
+  public abstract void setRouterId(String routerId);
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/GetRouterRegistrationResponse.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.server.federation.store.protocol;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+
+/**
+ * API response for retrieving a single router registration present in the state
+ * store.
+ */
+public abstract class GetRouterRegistrationResponse {
+
+  public static GetRouterRegistrationResponse newInstance() throws IOException {
+    return StateStoreSerializer.newRecord(GetRouterRegistrationResponse.class);
+  }
+
+  @Public
+  @Unstable
+  public abstract RouterState getRouter() throws IOException;
+
+  @Public
+  @Unstable
+  public abstract void setRouter(RouterState router) throws IOException;
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/GetRouterRegistrationsRequest.java

@@ -0,0 +1,34 @@
+/**
+ * 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.store.protocol;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+
+/**
+ * API request for retrieving a all non-expired router registrations present in
+ * the state store.
+ */
+public abstract class GetRouterRegistrationsRequest {
+
+  public static GetRouterRegistrationsRequest newInstance() throws IOException {
+    return StateStoreSerializer.newRecord(GetRouterRegistrationsRequest.class);
+  }
+
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/GetRouterRegistrationsResponse.java

@@ -0,0 +1,55 @@
+/**
+ * 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.store.protocol;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+
+/**
+ * API response for retrieving a all non-expired router registrations present in
+ * the state store.
+ */
+public abstract class GetRouterRegistrationsResponse {
+
+  public static GetRouterRegistrationsResponse newInstance()
+      throws IOException {
+    return StateStoreSerializer.newRecord(GetRouterRegistrationsResponse.class);
+  }
+
+  @Public
+  @Unstable
+  public abstract List<RouterState> getRouters() throws IOException;
+
+  @Public
+  @Unstable
+  public abstract void setRouters(List<RouterState> routers)
+      throws IOException;
+
+  @Public
+  @Unstable
+  public abstract long getTimestamp();
+
+  @Public
+  @Unstable
+  public abstract void setTimestamp(long time);
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/RouterHeartbeatRequest.java

@@ -0,0 +1,50 @@
+/**
+ * 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.store.protocol;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+
+/**
+ * API request for registering a router with the state store.
+ */
+public abstract class RouterHeartbeatRequest {
+
+  public static RouterHeartbeatRequest newInstance() throws IOException {
+    return StateStoreSerializer.newRecord(RouterHeartbeatRequest.class);
+  }
+
+  public static RouterHeartbeatRequest newInstance(RouterState router)
+      throws IOException {
+    RouterHeartbeatRequest request = newInstance();
+    request.setRouter(router);
+    return request;
+  }
+
+  @Public
+  @Unstable
+  public abstract RouterState getRouter() throws IOException;
+
+  @Public
+  @Unstable
+  public abstract void setRouter(RouterState routerState);
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/RouterHeartbeatResponse.java

@@ -0,0 +1,49 @@
+/**
+ * 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.store.protocol;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+
+/**
+ * API response for registering a router with the state store.
+ */
+public abstract class RouterHeartbeatResponse {
+
+  public static RouterHeartbeatResponse newInstance() throws IOException {
+    return StateStoreSerializer.newRecord(RouterHeartbeatResponse.class);
+  }
+
+  public static RouterHeartbeatResponse newInstance(boolean status)
+      throws IOException {
+    RouterHeartbeatResponse response = newInstance();
+    response.setStatus(status);
+    return response;
+  }
+
+  @Public
+  @Unstable
+  public abstract boolean getStatus();
+
+  @Public
+  @Unstable
+  public abstract void setStatus(boolean result);
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/GetRouterRegistrationRequestPBImpl.java

@@ -0,0 +1,70 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationRequestProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationRequestProtoOrBuilder;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationRequest;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * GetRouterRegistrationRequest.
+ */
+public class GetRouterRegistrationRequestPBImpl
+    extends GetRouterRegistrationRequest implements PBRecord {
+
+  private FederationProtocolPBTranslator<GetRouterRegistrationRequestProto,
+      Builder, GetRouterRegistrationRequestProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<GetRouterRegistrationRequestProto,
+              Builder, GetRouterRegistrationRequestProtoOrBuilder>(
+                  GetRouterRegistrationRequestProto.class);
+
+  public GetRouterRegistrationRequestPBImpl() {
+  }
+
+  @Override
+  public GetRouterRegistrationRequestProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public String getRouterId() {
+    return this.translator.getProtoOrBuilder().getRouterId();
+  }
+
+  @Override
+  public void setRouterId(String routerId) {
+    this.translator.getBuilder().setRouterId(routerId);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/GetRouterRegistrationResponsePBImpl.java

@@ -0,0 +1,79 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationResponseProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationResponseProtoOrBuilder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProto;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.RouterStatePBImpl;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * GetRouterRegistrationResponse.
+ */
+public class GetRouterRegistrationResponsePBImpl
+    extends GetRouterRegistrationResponse implements PBRecord {
+
+  private FederationProtocolPBTranslator<GetRouterRegistrationResponseProto,
+      Builder, GetRouterRegistrationResponseProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<
+              GetRouterRegistrationResponseProto, Builder,
+              GetRouterRegistrationResponseProtoOrBuilder>(
+                  GetRouterRegistrationResponseProto.class);
+
+  public GetRouterRegistrationResponsePBImpl() {
+  }
+
+  @Override
+  public GetRouterRegistrationResponseProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message protocol) {
+    this.translator.setProto(protocol);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public RouterState getRouter() {
+    RouterRecordProto proto = this.translator.getProtoOrBuilder().getRouter();
+    return new RouterStatePBImpl(proto);
+  }
+
+  @Override
+  public void setRouter(RouterState router) {
+    if (router instanceof RouterStatePBImpl) {
+      RouterStatePBImpl routerPB = (RouterStatePBImpl)router;
+      RouterRecordProto routerProto = routerPB.getProto();
+      this.translator.getBuilder().setRouter(routerProto);
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/GetRouterRegistrationsRequestPBImpl.java

@@ -0,0 +1,61 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsRequestProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsRequestProtoOrBuilder;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsRequest;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * GetRouterRegistrationsRequest.
+ */
+public class GetRouterRegistrationsRequestPBImpl
+    extends GetRouterRegistrationsRequest implements PBRecord {
+
+  private FederationProtocolPBTranslator<GetRouterRegistrationsRequestProto,
+      Builder, GetRouterRegistrationsRequestProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<
+              GetRouterRegistrationsRequestProto, Builder,
+              GetRouterRegistrationsRequestProtoOrBuilder>(
+                  GetRouterRegistrationsRequestProto.class);
+
+  public GetRouterRegistrationsRequestPBImpl() {
+  }
+
+  @Override
+  public GetRouterRegistrationsRequestProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/GetRouterRegistrationsResponsePBImpl.java

@@ -0,0 +1,102 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsResponseProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.GetRouterRegistrationsResponseProtoOrBuilder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProto;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetRouterRegistrationsResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.RouterStatePBImpl;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * GetRouterRegistrationsResponse.
+ */
+public class GetRouterRegistrationsResponsePBImpl
+    extends GetRouterRegistrationsResponse implements PBRecord {
+
+  private FederationProtocolPBTranslator<GetRouterRegistrationsResponseProto,
+      Builder, GetRouterRegistrationsResponseProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<
+              GetRouterRegistrationsResponseProto, Builder,
+              GetRouterRegistrationsResponseProtoOrBuilder>(
+                  GetRouterRegistrationsResponseProto.class);
+
+  public GetRouterRegistrationsResponsePBImpl() {
+
+  }
+
+  @Override
+  public GetRouterRegistrationsResponseProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public List<RouterState> getRouters() throws IOException {
+
+    List<RouterState> ret = new ArrayList<RouterState>();
+    List<RouterRecordProto> memberships =
+        this.translator.getProtoOrBuilder().getRoutersList();
+    for (RouterRecordProto memberProto : memberships) {
+      RouterState membership = new RouterStatePBImpl(memberProto);
+      ret.add(membership);
+    }
+    return ret;
+  }
+
+  @Override
+  public void setRouters(List<RouterState> records) throws IOException {
+
+    this.translator.getBuilder().clearRouters();
+    for (RouterState router : records) {
+      if (router instanceof RouterStatePBImpl) {
+        RouterStatePBImpl routerPB = (RouterStatePBImpl) router;
+        this.translator.getBuilder().addRouters(routerPB.getProto());
+      }
+    }
+  }
+
+  @Override
+  public long getTimestamp() {
+    return this.translator.getProtoOrBuilder().getTimestamp();
+  }
+
+  @Override
+  public void setTimestamp(long time) {
+    this.translator.getBuilder().setTimestamp(time);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/RouterHeartbeatRequestPBImpl.java

@@ -0,0 +1,78 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatRequestProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatRequestProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatRequestProtoOrBuilder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProto;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatRequest;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.RouterStatePBImpl;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * RouterHeartbeatRequest.
+ */
+public class RouterHeartbeatRequestPBImpl extends RouterHeartbeatRequest
+    implements PBRecord {
+
+  private FederationProtocolPBTranslator<RouterHeartbeatRequestProto, Builder,
+      RouterHeartbeatRequestProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<RouterHeartbeatRequestProto,
+              Builder, RouterHeartbeatRequestProtoOrBuilder>(
+                  RouterHeartbeatRequestProto.class);
+
+  public RouterHeartbeatRequestPBImpl() {
+  }
+
+  @Override
+  public RouterHeartbeatRequestProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public RouterState getRouter() throws IOException {
+    RouterRecordProto routerProto =
+        this.translator.getProtoOrBuilder().getRouter();
+    return new RouterStatePBImpl(routerProto);
+  }
+
+  @Override
+  public void setRouter(RouterState routerState) {
+    if (routerState instanceof RouterStatePBImpl) {
+      RouterStatePBImpl routerStatePB = (RouterStatePBImpl)routerState;
+      this.translator.getBuilder().setRouter(routerStatePB.getProto());
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/RouterHeartbeatResponsePBImpl.java

@@ -0,0 +1,70 @@
+/**
+ * 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.store.protocol.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatResponseProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatResponseProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterHeartbeatResponseProtoOrBuilder;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RouterHeartbeatResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.impl.pb.PBRecord;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the state store API object
+ * RouterHeartbeatResponse.
+ */
+public class RouterHeartbeatResponsePBImpl extends RouterHeartbeatResponse
+    implements PBRecord {
+
+  private FederationProtocolPBTranslator<RouterHeartbeatResponseProto, Builder,
+      RouterHeartbeatResponseProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<RouterHeartbeatResponseProto,
+              Builder, RouterHeartbeatResponseProtoOrBuilder>(
+                  RouterHeartbeatResponseProto.class);
+
+  public RouterHeartbeatResponsePBImpl() {
+  }
+
+  @Override
+  public RouterHeartbeatResponseProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public boolean getStatus() {
+    return this.translator.getProtoOrBuilder().getStatus();
+  }
+
+  @Override
+  public void setStatus(boolean result) {
+    this.translator.getBuilder().setStatus(result);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/records/RouterState.java

@@ -0,0 +1,169 @@
+/**
+ * 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.store.records;
+
+import java.io.IOException;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+import org.apache.hadoop.hdfs.server.federation.router.FederationUtil;
+import org.apache.hadoop.hdfs.server.federation.router.RouterServiceState;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Entry to log the state of a
+ * {@link org.apache.hadoop.hdfs.server.federation.router.Router Router} in the
+ * {@link org.apache.hadoop.hdfs.server.federation.store.StateStoreService
+ * FederationStateStoreService}.
+ */
+public abstract class RouterState extends BaseRecord {
+
+  private static final Logger LOG = LoggerFactory.getLogger(RouterState.class);
+
+  /** Expiration time in ms for this entry. */
+  private static long expirationMs;
+
+  /**
+   * Constructors.
+   */
+  public RouterState() {
+    super();
+  }
+
+  public static RouterState newInstance() {
+    RouterState record = StateStoreSerializer.newRecord(RouterState.class);
+    record.init();
+    return record;
+  }
+
+  public static RouterState newInstance(String addr, long startTime,
+      RouterServiceState status) {
+    RouterState record = newInstance();
+    record.setDateStarted(startTime);
+    record.setAddress(addr);
+    record.setStatus(status);
+    record.setCompileInfo(FederationUtil.getCompileInfo());
+    record.setBuildVersion(FederationUtil.getBuildVersion());
+    return record;
+  }
+
+  public abstract void setAddress(String address);
+
+  public abstract void setDateStarted(long dateStarted);
+
+  public abstract String getAddress();
+
+  public abstract StateStoreVersion getStateStoreVersion() throws IOException;
+
+  public abstract void setStateStoreVersion(StateStoreVersion version);
+
+  public abstract RouterServiceState getStatus();
+
+  public abstract void setStatus(RouterServiceState newStatus);
+
+  public abstract String getBuildVersion();
+
+  public abstract void setBuildVersion(String version);
+
+  public abstract String getCompileInfo();
+
+  public abstract void setCompileInfo(String info);
+
+  public abstract long getDateStarted();
+
+  /**
+   * Get the identifier for the Router. It uses the address.
+   *
+   * @return Identifier for the Router.
+   */
+  public String getRouterId() {
+    return getAddress();
+  }
+
+  @Override
+  public boolean like(BaseRecord o) {
+    if (o instanceof RouterState) {
+      RouterState other = (RouterState)o;
+      if (getAddress() != null &&
+          !getAddress().equals(other.getAddress())) {
+        return false;
+      }
+      if (getStatus() != null &&
+          !getStatus().equals(other.getStatus())) {
+        return false;
+      }
+      return true;
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return getAddress() + " -> " + getStatus() + "," + getBuildVersion();
+  }
+
+  @Override
+  public SortedMap<String, String> getPrimaryKeys() {
+    SortedMap<String, String> map = new TreeMap<>();
+    map.put("address", getAddress());
+    return map;
+  }
+
+  @Override
+  public boolean validate() {
+    boolean ret = super.validate();
+    if ((getAddress() == null || getAddress().length() == 0) &&
+        getStatus() != RouterServiceState.INITIALIZING) {
+      LOG.error("Invalid router entry, no address specified {}", this);
+      ret = false;
+    }
+    return ret;
+  }
+
+  @Override
+  public int compareTo(BaseRecord other) {
+    if (other == null) {
+      return -1;
+    } else if (other instanceof RouterState) {
+      RouterState router = (RouterState) other;
+      return this.getAddress().compareTo(router.getAddress());
+    } else {
+      return super.compareTo(other);
+    }
+  }
+
+  @Override
+  public boolean checkExpired(long currentTime) {
+    if (super.checkExpired(currentTime)) {
+      setStatus(RouterServiceState.EXPIRED);
+      return true;
+    }
+    return false;
+  }
+
+  @Override
+  public long getExpirationMs() {
+    return RouterState.expirationMs;
+  }
+
+  public static void setExpirationMs(long time) {
+    RouterState.expirationMs = time;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/records/StateStoreVersion.java

@@ -0,0 +1,91 @@
+/**
+ * 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.store.records;
+
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+
+/**
+ * Entry to track the version of the State Store data stored in the State Store
+ * by a Router.
+ */
+public abstract class StateStoreVersion extends BaseRecord {
+
+  public static StateStoreVersion newInstance() {
+    return StateStoreSerializer.newRecord(StateStoreVersion.class);
+  }
+
+  public static StateStoreVersion newInstance(long membershipVersion,
+      long mountTableVersion) {
+    StateStoreVersion record = newInstance();
+    record.setMembershipVersion(membershipVersion);
+    record.setMountTableVersion(mountTableVersion);
+    return record;
+  }
+
+  public abstract long getMembershipVersion();
+
+  public abstract void setMembershipVersion(long version);
+
+  public abstract long getMountTableVersion();
+
+  public abstract void setMountTableVersion(long version);
+
+  @Override
+  public SortedMap<String, String> getPrimaryKeys() {
+    // This record is not stored directly, no key needed
+    SortedMap<String, String> map = new TreeMap<String, String>();
+    return map;
+  }
+
+  @Override
+  public long getExpirationMs() {
+    // This record is not stored directly, no expiration needed
+    return -1;
+  }
+
+  @Override
+  public void setDateModified(long time) {
+    // We don't store this record directly
+  }
+
+  @Override
+  public long getDateModified() {
+    // We don't store this record directly
+    return 0;
+  }
+
+  @Override
+  public void setDateCreated(long time) {
+    // We don't store this record directly
+  }
+
+  @Override
+  public long getDateCreated() {
+    // We don't store this record directly
+    return 0;
+  }
+
+  @Override
+  public String toString() {
+    return "Membership: " + getMembershipVersion() +
+        " Mount Table: " + getMountTableVersion();
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/records/impl/pb/RouterStatePBImpl.java

@@ -0,0 +1,202 @@
+/**
+ * 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.store.records.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.RouterRecordProtoOrBuilder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.StateStoreVersionRecordProto;
+import org.apache.hadoop.hdfs.server.federation.router.RouterServiceState;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.FederationProtocolPBTranslator;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+import org.apache.hadoop.hdfs.server.federation.store.records.StateStoreVersion;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the RouterState record.
+ */
+public class RouterStatePBImpl extends RouterState implements PBRecord {
+
+  private FederationProtocolPBTranslator<RouterRecordProto, Builder,
+      RouterRecordProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<RouterRecordProto, Builder,
+             RouterRecordProtoOrBuilder>(RouterRecordProto.class);
+
+  public RouterStatePBImpl() {
+  }
+
+  public RouterStatePBImpl(RouterRecordProto proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public RouterRecordProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public void setAddress(String address) {
+    RouterRecordProto.Builder builder = this.translator.getBuilder();
+    if (address == null) {
+      builder.clearAddress();
+    } else {
+      builder.setAddress(address);
+    }
+  }
+
+  @Override
+  public String getAddress() {
+    RouterRecordProtoOrBuilder proto = this.translator.getProtoOrBuilder();
+    if (!proto.hasAddress()) {
+      return null;
+    }
+    return proto.getAddress();
+  }
+
+  @Override
+  public void setStateStoreVersion(StateStoreVersion version) {
+    RouterRecordProto.Builder builder = this.translator.getBuilder();
+    if (version instanceof StateStoreVersionPBImpl) {
+      StateStoreVersionPBImpl versionPB = (StateStoreVersionPBImpl)version;
+      StateStoreVersionRecordProto versionProto =
+          (StateStoreVersionRecordProto)versionPB.getProto();
+      builder.setStateStoreVersion(versionProto);
+    } else {
+      builder.clearStateStoreVersion();
+    }
+  }
+
+  @Override
+  public StateStoreVersion getStateStoreVersion() throws IOException {
+    RouterRecordProtoOrBuilder proto = this.translator.getProtoOrBuilder();
+    if (!proto.hasStateStoreVersion()) {
+      return null;
+    }
+    StateStoreVersionRecordProto versionProto = proto.getStateStoreVersion();
+    StateStoreVersion version =
+        StateStoreSerializer.newRecord(StateStoreVersion.class);
+    if (version instanceof StateStoreVersionPBImpl) {
+      StateStoreVersionPBImpl versionPB = (StateStoreVersionPBImpl)version;
+      versionPB.setProto(versionProto);
+      return versionPB;
+    } else {
+      throw new IOException("Cannot get State Store version");
+    }
+  }
+
+  @Override
+  public RouterServiceState getStatus() {
+    RouterRecordProtoOrBuilder proto = this.translator.getProtoOrBuilder();
+    if (!proto.hasStatus()) {
+      return null;
+    }
+    return RouterServiceState.valueOf(proto.getStatus());
+  }
+
+  @Override
+  public void setStatus(RouterServiceState newStatus) {
+    RouterRecordProto.Builder builder = this.translator.getBuilder();
+    if (newStatus == null) {
+      builder.clearStatus();
+    } else {
+      builder.setStatus(newStatus.toString());
+    }
+  }
+
+  @Override
+  public String getBuildVersion() {
+    RouterRecordProtoOrBuilder proto = this.translator.getProtoOrBuilder();
+    if (!proto.hasBuildVersion()) {
+      return null;
+    }
+    return proto.getBuildVersion();
+  }
+
+  @Override
+  public void setBuildVersion(String version) {
+    RouterRecordProto.Builder builder = this.translator.getBuilder();
+    if (version == null) {
+      builder.clearBuildVersion();
+    } else {
+      builder.setBuildVersion(version);
+    }
+  }
+
+  @Override
+  public String getCompileInfo() {
+    RouterRecordProtoOrBuilder proto = this.translator.getProtoOrBuilder();
+    if (!proto.hasCompileInfo()) {
+      return null;
+    }
+    return proto.getCompileInfo();
+  }
+
+  @Override
+  public void setCompileInfo(String info) {
+    RouterRecordProto.Builder builder = this.translator.getBuilder();
+    if (info == null) {
+      builder.clearCompileInfo();
+    } else {
+      builder.setCompileInfo(info);
+    }
+  }
+
+  @Override
+  public void setDateStarted(long dateStarted) {
+    this.translator.getBuilder().setDateStarted(dateStarted);
+  }
+
+  @Override
+  public long getDateStarted() {
+    return this.translator.getProtoOrBuilder().getDateStarted();
+  }
+
+  @Override
+  public void setDateModified(long time) {
+    this.translator.getBuilder().setDateModified(time);
+  }
+
+  @Override
+  public long getDateModified() {
+    return this.translator.getProtoOrBuilder().getDateModified();
+  }
+
+  @Override
+  public void setDateCreated(long time) {
+    this.translator.getBuilder().setDateCreated(time);
+  }
+
+  @Override
+  public long getDateCreated() {
+    return this.translator.getProtoOrBuilder().getDateCreated();
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/records/impl/pb/StateStoreVersionPBImpl.java

@@ -0,0 +1,79 @@
+/**
+ * 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.store.records.impl.pb;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.StateStoreVersionRecordProto;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.StateStoreVersionRecordProto.Builder;
+import org.apache.hadoop.hdfs.federation.protocol.proto.HdfsServerFederationProtos.StateStoreVersionRecordProtoOrBuilder;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.impl.pb.FederationProtocolPBTranslator;
+import org.apache.hadoop.hdfs.server.federation.store.records.StateStoreVersion;
+
+import com.google.protobuf.Message;
+
+/**
+ * Protobuf implementation of the StateStoreVersion record.
+ */
+public class StateStoreVersionPBImpl extends StateStoreVersion
+    implements PBRecord {
+
+  private FederationProtocolPBTranslator<StateStoreVersionRecordProto, Builder,
+      StateStoreVersionRecordProtoOrBuilder> translator =
+          new FederationProtocolPBTranslator<StateStoreVersionRecordProto,
+              Builder, StateStoreVersionRecordProtoOrBuilder>(
+                  StateStoreVersionRecordProto.class);
+
+  public StateStoreVersionPBImpl() {
+  }
+
+  @Override
+  public StateStoreVersionRecordProto getProto() {
+    return this.translator.build();
+  }
+
+  @Override
+  public void setProto(Message proto) {
+    this.translator.setProto(proto);
+  }
+
+  @Override
+  public void readInstance(String base64String) throws IOException {
+    this.translator.readInstance(base64String);
+  }
+
+  @Override
+  public long getMembershipVersion() {
+    return this.translator.getProtoOrBuilder().getMembershipVersion();
+  }
+
+  @Override
+  public void setMembershipVersion(long version) {
+    this.translator.getBuilder().setMembershipVersion(version);
+  }
+
+  @Override
+  public long getMountTableVersion() {
+    return this.translator.getProtoOrBuilder().getMountTableVersion();
+  }
+
+  @Override
+  public void setMountTableVersion(long version) {
+    this.translator.getBuilder().setMountTableVersion(version);
+  }
+}

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

@@ -171,3 +171,47 @@ message GetMountTableEntriesResponseProto {
   optional uint64 timestamp = 2;
 }
 
+
+/////////////////////////////////////////////////
+// Routers
+/////////////////////////////////////////////////
+
+message StateStoreVersionRecordProto {
+  optional uint64 membershipVersion = 1;
+  optional uint64 mountTableVersion = 2;
+}
+
+message RouterRecordProto {
+  optional uint64 dateCreated = 1;
+  optional uint64 dateModified = 2;
+  optional string address = 3;
+  optional string status = 4;
+  optional StateStoreVersionRecordProto stateStoreVersion = 5;
+  optional string buildVersion = 6;
+  optional string compileInfo = 7;
+  optional uint64 dateStarted = 8;
+}
+
+message GetRouterRegistrationRequestProto {
+  optional string routerId = 1;
+}
+
+message GetRouterRegistrationResponseProto {
+  optional RouterRecordProto router = 1;
+}
+
+message GetRouterRegistrationsRequestProto {
+}
+
+message GetRouterRegistrationsResponseProto {
+  optional uint64 timestamp = 1;
+  repeated RouterRecordProto routers = 2;
+}
+
+message RouterHeartbeatRequestProto {
+  optional RouterRecordProto router = 1;
+}
+
+message RouterHeartbeatResponseProto {
+  optional bool status = 1;
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/store/driver/TestStateStoreDriverBase.java

@@ -37,6 +37,7 @@ import java.util.Random;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.federation.metrics.StateStoreMetrics;
 import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamenodeServiceState;
+import org.apache.hadoop.hdfs.server.federation.router.RouterServiceState;
 import org.apache.hadoop.hdfs.server.federation.store.FederationStateStoreTestUtils;
 import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
 import org.apache.hadoop.hdfs.server.federation.store.records.BaseRecord;
@@ -44,6 +45,8 @@ import org.apache.hadoop.hdfs.server.federation.store.records.MembershipState;
 import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
 import org.apache.hadoop.hdfs.server.federation.store.records.Query;
 import org.apache.hadoop.hdfs.server.federation.store.records.QueryResult;
+import org.apache.hadoop.hdfs.server.federation.store.records.RouterState;
+import org.apache.hadoop.hdfs.server.federation.store.records.StateStoreVersion;
 import org.junit.AfterClass;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -94,6 +97,10 @@ public class TestStateStoreDriverBase {
     return randomString;
   }
 
+  private long generateRandomLong() {
+    return RANDOM.nextLong();
+  }
+
   @SuppressWarnings("rawtypes")
   private <T extends Enum> T generateRandomEnum(Class<T> enumClass) {
     int x = RANDOM.nextInt(enumClass.getEnumConstants().length);
@@ -117,6 +124,12 @@ public class TestStateStoreDriverBase {
       Map<String, String> destMap = Collections.singletonMap(
           generateRandomString(), "/" + generateRandomString());
       return (T) MountTable.newInstance(src, destMap);
+    } else if (recordClass == RouterState.class) {
+      RouterState routerState = RouterState.newInstance(generateRandomString(),
+          generateRandomLong(), generateRandomEnum(RouterServiceState.class));
+      StateStoreVersion version = generateFakeRecord(StateStoreVersion.class);
+      routerState.setStateStoreVersion(version);
+      return (T) routerState;
     }
 
     return null;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/store/records/TestRouterState.java

@@ -0,0 +1,85 @@
+/**
+ * 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.store.records;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.server.federation.router.RouterServiceState;
+import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+import org.junit.Test;
+
+/**
+ * Test the Router State records.
+ */
+public class TestRouterState {
+
+  private static final String ADDRESS = "address";
+  private static final String BUILD_VERSION = "buildVersion";
+  private static final String COMPILE_INFO = "compileInfo";
+  private static final long START_TIME = 100;
+  private static final long DATE_MODIFIED = 200;
+  private static final long DATE_CREATED = 300;
+  private static final long FILE_RESOLVER_VERSION = 500;
+  private static final RouterServiceState STATE = RouterServiceState.RUNNING;
+
+
+  private RouterState generateRecord() throws IOException {
+    RouterState record = RouterState.newInstance(ADDRESS, START_TIME, STATE);
+    record.setBuildVersion(BUILD_VERSION);
+    record.setCompileInfo(COMPILE_INFO);
+    record.setDateCreated(DATE_CREATED);
+    record.setDateModified(DATE_MODIFIED);
+
+    StateStoreVersion version = StateStoreVersion.newInstance();
+    version.setMountTableVersion(FILE_RESOLVER_VERSION);
+    record.setStateStoreVersion(version);
+    return record;
+  }
+
+  private void validateRecord(RouterState record) throws IOException {
+    assertEquals(ADDRESS, record.getAddress());
+    assertEquals(START_TIME, record.getDateStarted());
+    assertEquals(STATE, record.getStatus());
+    assertEquals(COMPILE_INFO, record.getCompileInfo());
+    assertEquals(BUILD_VERSION, record.getBuildVersion());
+
+    StateStoreVersion version = record.getStateStoreVersion();
+    assertEquals(FILE_RESOLVER_VERSION, version.getMountTableVersion());
+  }
+
+  @Test
+  public void testGetterSetter() throws IOException {
+    RouterState record = generateRecord();
+    validateRecord(record);
+  }
+
+  @Test
+  public void testSerialization() throws IOException {
+
+    RouterState record = generateRecord();
+
+    StateStoreSerializer serializer = StateStoreSerializer.getSerializer();
+    String serializedString = serializer.serializeString(record);
+    RouterState newRecord =
+        serializer.deserialize(serializedString, RouterState.class);
+
+    validateRecord(newRecord);
+  }
+}