| /** |
| * 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 static org.apache.hadoop.fs.CommonConfigurationKeysPublic.NET_TOPOLOGY_TABLE_MAPPING_FILE_KEY; |
| |
| import java.io.BufferedReader; |
| import java.io.FileInputStream; |
| import java.io.InputStreamReader; |
| import java.nio.charset.StandardCharsets; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.commons.lang.StringUtils; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| |
| /** |
| * <p> |
| * Simple {@link DNSToSwitchMapping} implementation that reads a 2 column text |
| * file. The columns are separated by whitespace. The first column is a DNS or |
| * IP address and the second column specifies the rack where the address maps. |
| * </p> |
| * <p> |
| * This class uses the configuration parameter {@code |
| * net.topology.table.file.name} to locate the mapping file. |
| * </p> |
| * <p> |
| * Calls to {@link #resolve(List)} will look up the address as defined in the |
| * mapping file. If no entry corresponding to the address is found, the value |
| * {@code /default-rack} is returned. |
| * </p> |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class TableMapping extends CachedDNSToSwitchMapping { |
| |
| private static final Log LOG = LogFactory.getLog(TableMapping.class); |
| |
| public TableMapping() { |
| super(new RawTableMapping()); |
| } |
| |
| private RawTableMapping getRawMapping() { |
| return (RawTableMapping) rawMapping; |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return getRawMapping().getConf(); |
| } |
| |
| @Override |
| public void setConf(Configuration conf) { |
| super.setConf(conf); |
| getRawMapping().setConf(conf); |
| } |
| |
| @Override |
| public void reloadCachedMappings() { |
| super.reloadCachedMappings(); |
| getRawMapping().reloadCachedMappings(); |
| } |
| |
| private static final class RawTableMapping extends Configured |
| implements DNSToSwitchMapping { |
| |
| private Map<String, String> map; |
| |
| private Map<String, String> load() { |
| Map<String, String> loadMap = new HashMap<String, String>(); |
| |
| String filename = getConf().get(NET_TOPOLOGY_TABLE_MAPPING_FILE_KEY, null); |
| if (StringUtils.isBlank(filename)) { |
| LOG.warn(NET_TOPOLOGY_TABLE_MAPPING_FILE_KEY + " not configured. "); |
| return null; |
| } |
| |
| |
| try (BufferedReader reader = |
| new BufferedReader(new InputStreamReader( |
| new FileInputStream(filename), StandardCharsets.UTF_8))) { |
| String line = reader.readLine(); |
| while (line != null) { |
| line = line.trim(); |
| if (line.length() != 0 && line.charAt(0) != '#') { |
| String[] columns = line.split("\\s+"); |
| if (columns.length == 2) { |
| loadMap.put(columns[0], columns[1]); |
| } else { |
| LOG.warn("Line does not have two columns. Ignoring. " + line); |
| } |
| } |
| line = reader.readLine(); |
| } |
| } catch (Exception e) { |
| LOG.warn(filename + " cannot be read.", e); |
| return null; |
| } |
| return loadMap; |
| } |
| |
| @Override |
| public synchronized List<String> resolve(List<String> names) { |
| if (map == null) { |
| map = load(); |
| if (map == null) { |
| LOG.warn("Failed to read topology table. " + |
| NetworkTopology.DEFAULT_RACK + " will be used for all nodes."); |
| map = new HashMap<String, String>(); |
| } |
| } |
| List<String> results = new ArrayList<String>(names.size()); |
| for (String name : names) { |
| String result = map.get(name); |
| if (result != null) { |
| results.add(result); |
| } else { |
| results.add(NetworkTopology.DEFAULT_RACK); |
| } |
| } |
| return results; |
| } |
| |
| @Override |
| public void reloadCachedMappings() { |
| Map<String, String> newMap = load(); |
| if (newMap == null) { |
| LOG.error("Failed to reload the topology table. The cached " + |
| "mappings will not be cleared."); |
| } else { |
| synchronized(this) { |
| map = newMap; |
| } |
| } |
| } |
| |
| @Override |
| public void reloadCachedMappings(List<String> names) { |
| // TableMapping has to reload all mappings at once, so no chance to |
| // reload mappings on specific nodes |
| reloadCachedMappings(); |
| } |
| } |
| } |