hadoop DNSToSwitchMapping 源码

  • 2022-10-20
  • 浏览 (452)

haddop DNSToSwitchMapping 代码

文件路径:/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNSToSwitchMapping.java

/**
 * 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.net;

import java.util.List;

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

/**
 * An interface that must be implemented to allow pluggable
 * DNS-name/IP-address to RackID resolvers.
 *
 */
@InterfaceAudience.Public
@InterfaceStability.Evolving
public interface DNSToSwitchMapping {
  /**
   * Resolves a list of DNS-names/IP-addresses and returns back a list of
   * switch information (network paths). One-to-one correspondence must be 
   * maintained between the elements in the lists. 
   * Consider an element in the argument list - x.y.com. The switch information
   * that is returned must be a network path of the form /foo/rack, 
   * where / is the root, and 'foo' is the switch where 'rack' is connected.
   * Note the hostname/ip-address is not part of the returned path.
   * The network topology of the cluster would determine the number of
   * components in the network path.
   * <p>
   *
   * If a name cannot be resolved to a rack, the implementation
   * should return {@link NetworkTopology#DEFAULT_RACK}. This
   * is what the bundled implementations do, though it is not a formal requirement
   *
   * @param names the list of hosts to resolve (can be empty)
   * @return list of resolved network paths.
   * If <i>names</i> is empty, the returned list is also empty
   */
  public List<String> resolve(List<String> names);

  /**
   * Reload all of the cached mappings.
   *
   * If there is a cache, this method will clear it, so that future accesses
   * will get a chance to see the new data.
   */
  public void reloadCachedMappings();
  
  /**
   * Reload cached mappings on specific nodes.
   *
   * If there is a cache on these nodes, this method will clear it, so that 
   * future accesses will see updated data.
   *
   * @param names input names.
   */
  public void reloadCachedMappings(List<String> names);
}

相关信息

hadoop 源码目录

相关文章

hadoop AbstractDNSToSwitchMapping 源码

hadoop CachedDNSToSwitchMapping 源码

hadoop ConnectTimeoutException 源码

hadoop DNS 源码

hadoop DNSDomainNameResolver 源码

hadoop DNSToSwitchMappingWithDependency 源码

hadoop DomainNameResolver 源码

hadoop DomainNameResolverFactory 源码

hadoop InnerNode 源码

hadoop InnerNodeImpl 源码

0  赞