| /** |
| * 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.*; |
| import java.io.*; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.util.*; |
| import org.apache.hadoop.util.Shell.ShellCommandExecutor; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.*; |
| import org.apache.hadoop.fs.CommonConfigurationKeys; |
| |
| /** |
| * This class implements the {@link DNSToSwitchMapping} interface using a |
| * script configured via net.topology.script.file.name . |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public final class ScriptBasedMapping extends CachedDNSToSwitchMapping |
| implements Configurable |
| { |
| public ScriptBasedMapping() { |
| super(new RawScriptBasedMapping()); |
| } |
| |
| // script must accept at least this many args |
| static final int MIN_ALLOWABLE_ARGS = 1; |
| |
| static final int DEFAULT_ARG_COUNT = |
| CommonConfigurationKeys.NET_TOPOLOGY_SCRIPT_NUMBER_ARGS_DEFAULT; |
| |
| static final String SCRIPT_FILENAME_KEY = |
| CommonConfigurationKeys.NET_TOPOLOGY_SCRIPT_FILE_NAME_KEY ; |
| static final String SCRIPT_ARG_COUNT_KEY = |
| CommonConfigurationKeys.NET_TOPOLOGY_SCRIPT_NUMBER_ARGS_KEY ; |
| |
| public ScriptBasedMapping(Configuration conf) { |
| this(); |
| setConf(conf); |
| } |
| |
| public Configuration getConf() { |
| return ((RawScriptBasedMapping)rawMapping).getConf(); |
| } |
| |
| public void setConf(Configuration conf) { |
| ((RawScriptBasedMapping)rawMapping).setConf(conf); |
| } |
| |
| private static final class RawScriptBasedMapping |
| implements DNSToSwitchMapping { |
| private String scriptName; |
| private Configuration conf; |
| private int maxArgs; //max hostnames per call of the script |
| private static Log LOG = |
| LogFactory.getLog(ScriptBasedMapping.class); |
| public void setConf (Configuration conf) { |
| this.scriptName = conf.get(SCRIPT_FILENAME_KEY); |
| this.maxArgs = conf.getInt(SCRIPT_ARG_COUNT_KEY, DEFAULT_ARG_COUNT); |
| this.conf = conf; |
| } |
| public Configuration getConf () { |
| return conf; |
| } |
| |
| public RawScriptBasedMapping() {} |
| |
| public List<String> resolve(List<String> names) { |
| List <String> m = new ArrayList<String>(names.size()); |
| |
| if (names.isEmpty()) { |
| return m; |
| } |
| |
| if (scriptName == null) { |
| for (int i = 0; i < names.size(); i++) { |
| m.add(NetworkTopology.DEFAULT_RACK); |
| } |
| return m; |
| } |
| |
| String output = runResolveCommand(names); |
| if (output != null) { |
| StringTokenizer allSwitchInfo = new StringTokenizer(output); |
| while (allSwitchInfo.hasMoreTokens()) { |
| String switchInfo = allSwitchInfo.nextToken(); |
| m.add(switchInfo); |
| } |
| |
| if (m.size() != names.size()) { |
| // invalid number of entries returned by the script |
| LOG.warn("Script " + scriptName + " returned " |
| + Integer.toString(m.size()) + " values when " |
| + Integer.toString(names.size()) + " were expected."); |
| return null; |
| } |
| } else { |
| // an error occurred. return null to signify this. |
| // (exn was already logged in runResolveCommand) |
| return null; |
| } |
| |
| return m; |
| } |
| |
| private String runResolveCommand(List<String> args) { |
| int loopCount = 0; |
| if (args.size() == 0) { |
| return null; |
| } |
| StringBuilder allOutput = new StringBuilder(); |
| int numProcessed = 0; |
| if (maxArgs < MIN_ALLOWABLE_ARGS) { |
| LOG.warn("Invalid value " + Integer.toString(maxArgs) |
| + " for " + SCRIPT_ARG_COUNT_KEY + "; must be >= " |
| + Integer.toString(MIN_ALLOWABLE_ARGS)); |
| return null; |
| } |
| |
| while (numProcessed != args.size()) { |
| int start = maxArgs * loopCount; |
| List <String> cmdList = new ArrayList<String>(); |
| cmdList.add(scriptName); |
| for (numProcessed = start; numProcessed < (start + maxArgs) && |
| numProcessed < args.size(); numProcessed++) { |
| cmdList.add(args.get(numProcessed)); |
| } |
| File dir = null; |
| String userDir; |
| if ((userDir = System.getProperty("user.dir")) != null) { |
| dir = new File(userDir); |
| } |
| ShellCommandExecutor s = new ShellCommandExecutor( |
| cmdList.toArray(new String[0]), dir); |
| try { |
| s.execute(); |
| allOutput.append(s.getOutput() + " "); |
| } catch (Exception e) { |
| LOG.warn(StringUtils.stringifyException(e)); |
| return null; |
| } |
| loopCount++; |
| } |
| return allOutput.toString(); |
| } |
| } |
| } |