org.apache.hadoop.hdfs.protocol.ReconfigurationProtocol Maven / Gradle / Ivy
/**
* 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 listReconfigurableProperties() throws IOException;
}