http://git-wip-us.apache.org/repos/asf/hadoop/blob/b85b5f31/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/UpdateNamenodeRegistrationResponse.java
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diff --git
a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/UpdateNamenodeRegistrationResponse.java
b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/UpdateNamenodeRegistrationResponse.java
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+/**
+ * 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.Private;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import
org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreSerializer;
+
+/**
+ * API response for overriding an existing namenode registration in the state
+ * store.
+ */
+public abstract class UpdateNamenodeRegistrationResponse {
+
+ public static UpdateNamenodeRegistrationResponse newInstance() {
+return StateStoreSerializer.newRecord(
+UpdateNamenodeRegistrationResponse.class);
+ }
+
+ public static UpdateNamenodeRegistrationResponse newInstance(boolean status)
+ throws IOException {
+UpdateNamenodeRegistrationResponse response = newInstance();
+response.setResult(status);
+return response;
+ }
+
+ @Private
+ @Unstable
+ public abstract boolean getResult();
+
+ @Private
+ @Unstable
+ public abstract void setResult(boolean result);
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/hadoop/blob/b85b5f31/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/FederationProtocolPBTranslator.java
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b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/store/protocol/impl/pb/FederationProtocolPBTranslator.java
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+/**
+ * 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.lang.reflect.Method;
+
+import org.apache.commons.codec.binary.Base64;
+
+import com.google.protobuf.GeneratedMessage;
+import com.google.protobuf.Message;
+import com.google.protobuf.Message.Builder;
+import com.google.protobuf.MessageOrBuilder;
+
+/**
+ * Helper class for setting/getting data elements in an object backed by a
+ * protobuf implementation.
+ */
+public class FederationProtocolPBTranslator {
+
+ /** Optional proto byte stream used to create this object. */
+ private P proto;
+ /** The class of the proto handler for this