diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java
index 13f8f377497..9a29c039755 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java
@@ -875,7 +875,7 @@ public boolean saveNamespace(long timeWindow, long txGap) throws IOException {
     rpcServer.checkOperation(NameNode.OperationCategory.UNCHECKED);
 
     RemoteMethod method = new RemoteMethod("saveNamespace",
-        new Class<?>[] {Long.class, Long.class}, timeWindow, txGap);
+        new Class<?>[] {long.class, long.class}, timeWindow, txGap);
     final Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
     Map<FederationNamespaceInfo, Boolean> ret =
         rpcClient.invokeConcurrent(nss, method, true, false, boolean.class);
diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java
index c4d3a201783..0b153339428 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java
@@ -1045,7 +1045,7 @@ public <T extends RemoteLocationContext, R> Map<T, R> invokeConcurrent(
       Class<?> proto = method.getProtocol();
       Object[] paramList = method.getParams(location);
       Object result = invokeMethod(ugi, namenodes, proto, m, paramList);
-      return Collections.singletonMap(location, clazz.cast(result));
+      return Collections.singletonMap(location, (R) result);
     }
 
     List<T> orderedLocations = new LinkedList<>();
@@ -1103,7 +1103,7 @@ public Object call() throws Exception {
         try {
           Future<Object> future = futures.get(i);
           Object result = future.get();
-          results.put(location, clazz.cast(result));
+          results.put(location, (R) result);
         } catch (CancellationException ce) {
           T loc = orderedLocations.get(i);
           String msg = "Invocation to \"" + loc + "\" for \""
diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java
index 8632203b06d..760d755cb8f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java
@@ -111,6 +111,8 @@
 /**
  * The the RPC interface of the {@link Router} implemented by
  * {@link RouterRpcServer}.
+ * Tests covering the functionality of RouterRPCServer with
+ * multi nameServices.
  */
 public class TestRouterRpc {
 
@@ -1255,6 +1257,31 @@ public void testErasureCoding() throws IOException {
     assertEquals(statsNamenode.toString(), statsRouter.toString());
   }
 
+  @Test
+  public void testGetCurrentTXIDandRollEdits() throws IOException {
+    Long rollEdits = routerProtocol.rollEdits();
+    Long currentTXID = routerProtocol.getCurrentEditLogTxid();
+
+    assertEquals(rollEdits, currentTXID);
+  }
+
+  @Test
+  public void testSaveNamespace() throws IOException {
+    cluster.getCluster().getFileSystem(0)
+        .setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_ENTER);
+    cluster.getCluster().getFileSystem(1)
+        .setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_ENTER);
+
+    Boolean saveNamespace = routerProtocol.saveNamespace(0, 0);
+
+    assertTrue(saveNamespace);
+
+    cluster.getCluster().getFileSystem(0)
+        .setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_LEAVE);
+    cluster.getCluster().getFileSystem(1)
+        .setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_LEAVE);
+  }
+
   @Test
   public void testNamenodeMetrics() throws Exception {
     final NamenodeBeanMetrics metrics =
diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpcSingleNS.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpcSingleNS.java
new file mode 100644
index 00000000000..ae0afa42e4b
--- /dev/null
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpcSingleNS.java
@@ -0,0 +1,211 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.federation.router;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.hdfs.NameNodeProxies;
+import org.apache.hadoop.hdfs.protocol.ClientProtocol;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+import static org.apache.hadoop.hdfs.server.federation.FederationTestUtils.createFile;
+import static org.apache.hadoop.hdfs.server.federation.FederationTestUtils.verifyFileExists;
+
+/**
+ * The the RPC interface of the {@link Router} implemented by
+ * {@link RouterRpcServer}.
+ * Tests covering the functionality of RouterRPCServer with
+ * single nameService.
+ */
+public class TestRouterRpcSingleNS {
+
+  /**
+   * Federated HDFS cluster.
+   */
+  private static MiniRouterDFSCluster cluster;
+
+  /**
+   * Random Router for this federated cluster.
+   */
+  private MiniRouterDFSCluster.RouterContext router;
+
+  /**
+   * Random nameservice in the federated cluster.
+   */
+  private String ns;
+  /**
+   * First namenode in the nameservice.
+   */
+  private MiniRouterDFSCluster.NamenodeContext namenode;
+
+  /**
+   * Client interface to the Router.
+   */
+  private ClientProtocol routerProtocol;
+  /**
+   * Client interface to the Namenode.
+   */
+  private ClientProtocol nnProtocol;
+
+  /**
+   * NameNodeProtocol interface to the Router.
+   */
+  private NamenodeProtocol routerNamenodeProtocol;
+  /**
+   * NameNodeProtocol interface to the Namenode.
+   */
+  private NamenodeProtocol nnNamenodeProtocol;
+
+  /**
+   * Filesystem interface to the Router.
+   */
+  private FileSystem routerFS;
+  /**
+   * Filesystem interface to the Namenode.
+   */
+  private FileSystem nnFS;
+
+  /**
+   * File in the Router.
+   */
+  private String routerFile;
+  /**
+   * File in the Namenode.
+   */
+  private String nnFile;
+
+  @BeforeClass
+  public static void globalSetUp() throws Exception {
+    cluster = new MiniRouterDFSCluster(false, 1);
+    cluster.setNumDatanodesPerNameservice(2);
+
+    // Start NNs and DNs and wait until ready
+    cluster.startCluster();
+
+    // Start routers with only an RPC service
+    Configuration routerConf = new RouterConfigBuilder().metrics().rpc()
+        .build();
+    // We decrease the DN cache times to make the test faster
+    routerConf.setTimeDuration(RBFConfigKeys.DN_REPORT_CACHE_EXPIRE, 1,
+        TimeUnit.SECONDS);
+    cluster.addRouterOverrides(routerConf);
+    cluster.startRouters();
+
+    // Register and verify all NNs with all routers
+    cluster.registerNamenodes();
+    cluster.waitNamenodeRegistration();
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    cluster.shutdown();
+  }
+
+  @Before
+  public void testSetup() throws Exception {
+
+    // Create mock locations
+    cluster.installMockLocations();
+
+    // Delete all files via the NNs and verify
+    cluster.deleteAllFiles();
+
+    // Create test fixtures on NN
+    cluster.createTestDirectoriesNamenode();
+
+    // Wait to ensure NN has fully created its test directories
+    Thread.sleep(100);
+
+    // Random router for this test
+    MiniRouterDFSCluster.RouterContext rndRouter = cluster.getRandomRouter();
+    this.setRouter(rndRouter);
+
+    // Pick a namenode for this test
+    String ns0 = cluster.getNameservices().get(0);
+    this.setNs(ns0);
+    this.setNamenode(cluster.getNamenode(ns0, null));
+
+    // Create a test file on the NN
+    Random rnd = new Random();
+    String randomFile = "testfile-" + rnd.nextInt();
+    this.nnFile = cluster.getNamenodeTestDirectoryForNS(ns) + "/" + randomFile;
+    this.routerFile = cluster.getFederatedTestDirectoryForNS(ns) + "/"
+        + randomFile;
+
+    createFile(nnFS, nnFile, 32);
+    verifyFileExists(nnFS, nnFile);
+  }
+
+  protected void setRouter(MiniRouterDFSCluster.RouterContext r)
+      throws IOException, URISyntaxException {
+    this.router = r;
+    this.routerProtocol = r.getClient().getNamenode();
+    this.routerFS = r.getFileSystem();
+    this.routerNamenodeProtocol = NameNodeProxies.createProxy(router.getConf(),
+        router.getFileSystem().getUri(), NamenodeProtocol.class).getProxy();
+  }
+
+  protected void setNs(String nameservice) {
+    this.ns = nameservice;
+  }
+
+  protected void setNamenode(MiniRouterDFSCluster.NamenodeContext nn)
+      throws IOException, URISyntaxException {
+    this.namenode = nn;
+    this.nnProtocol = nn.getClient().getNamenode();
+    this.nnFS = nn.getFileSystem();
+
+    // Namenode from the default namespace
+    String ns0 = cluster.getNameservices().get(0);
+    MiniRouterDFSCluster.NamenodeContext nn0 = cluster.getNamenode(ns0, null);
+    this.nnNamenodeProtocol = NameNodeProxies.createProxy(nn0.getConf(),
+        nn0.getFileSystem().getUri(), NamenodeProtocol.class).getProxy();
+  }
+
+  @Test
+  public void testGetCurrentTXIDandRollEdits() throws IOException {
+    Long rollEdits = routerProtocol.rollEdits();
+    Long currentTXID = routerProtocol.getCurrentEditLogTxid();
+
+    assertEquals(rollEdits, currentTXID);
+  }
+
+  @Test
+  public void testSaveNamespace() throws IOException {
+    cluster.getCluster().getFileSystem()
+        .setSafeMode(HdfsConstants.SafeModeAction.SAFEMODE_ENTER);
+    Boolean saveNamespace = routerProtocol.saveNamespace(0, 0);
+
+    assertTrue(saveNamespace);
+  }
+}
\ No newline at end of file