/**
 * 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.
 */

/**
 * The resolver package contains indepedent data resolvers used in HDFS
 * federation. The data resolvers collect data from the cluster, including from
 * the state store. The resolvers expose APIs used by HDFS federation to collect
 * aggregated, cached data for use in Real-time request processing. The
 * resolvers are perf-sensitive and are used in the flow of the
 * {@link RouterRpcServer} request path.
 * <p>
 * The principal resolvers are:
 * <ul>
 * <li>{@link ActiveNamenodeResolver} Real-time interface for locating the most
 * recently active NN for a nameservice.
 * <li>{@link FileSubclusterResolver} Real-time interface for determining the NN
 * and local file path for a given file/folder based on the global namespace
 * path.
 * </ul>
 */
@InterfaceAudience.Private
@InterfaceStability.Evolving
package org.apache.hadoop.hdfs.server.federation.resolver;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
