/**
* 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.tools;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.retry.Idempotent;
/**
* Protocol implemented by the Name Node and Job Tracker which maps users to
* groups.
*/
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Evolving
public interface GetUserMappingsProtocol {
/**
* Version 1: Initial version.
*/
public static final long versionID = 1L;
/**
* Get the groups which are mapped to the given user.
* @param user The user to get the groups for.
* @return The set of groups the user belongs to.
* @throws IOException
*/
@Idempotent
public String[] getGroupsForUser(String user) throws IOException;
}