| /** |
| * 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.protocol; |
| |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.ReconfigurationTaskStatus; |
| import org.apache.hadoop.io.retry.Idempotent; |
| |
| /********************************************************************** |
| * ReconfigurationProtocol is used by HDFS admin to reload configuration |
| * for NN/DN without restarting them. |
| **********************************************************************/ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public interface ReconfigurationProtocol { |
| |
| long VERSIONID = 1L; |
| |
| /** |
| * Asynchronously reload configuration on disk and apply changes. |
| */ |
| @Idempotent |
| void startReconfiguration() throws IOException; |
| |
| /** |
| * Get the status of the previously issued reconfig task. |
| * @see {@link org.apache.hadoop.conf.ReconfigurationTaskStatus}. |
| */ |
| @Idempotent |
| ReconfigurationTaskStatus getReconfigurationStatus() throws IOException; |
| |
| /** |
| * Get a list of allowed properties for reconfiguration. |
| */ |
| @Idempotent |
| List<String> listReconfigurableProperties() throws IOException; |
| } |