HDFS-15839. RBF: Cannot get method setBalancerBandwidth on Router Client. Contributed by Yang Yun.

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

@@ -1183,7 +1183,7 @@ public class RouterClientProtocol implements ClientProtocol {
     rpcServer.checkOperation(NameNode.OperationCategory.UNCHECKED);
 
     RemoteMethod method = new RemoteMethod("setBalancerBandwidth",
-        new Class<?>[] {Long.class}, bandwidth);
+        new Class<?>[] {long.class}, bandwidth);
     final Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
     rpcClient.invokeConcurrent(nss, method, true, false);
   }

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

@@ -99,6 +99,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.security.token.block.ExportedBlockKeys;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
+import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster;
 import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster.NamenodeContext;
 import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster.RouterContext;
@@ -1934,4 +1935,16 @@ public class TestRouterRpc {
         .contains("callerContext=clientContext,clientIp:"));
     assertTrue(verifyFileExists(routerFS, dirPath));
   }
+
+  @Test
+  public void testSetBalancerBandwidth() throws Exception {
+    long defaultBandwidth =
+        DFSConfigKeys.DFS_DATANODE_BALANCE_BANDWIDTHPERSEC_DEFAULT;
+    long newBandwidth = defaultBandwidth * 2;
+    routerProtocol.setBalancerBandwidth(newBandwidth);
+    ArrayList<DataNode> datanodes = cluster.getCluster().getDataNodes();
+    GenericTestUtils.waitFor(() ->  {
+      return datanodes.get(0).getBalancerBandwidth() == newBandwidth;
+    }, 100, 60 * 1000);
+  }
 }