| /** |
| * 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.mapred.gridmix; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.security.UserGroupInformation; |
| import org.apache.hadoop.util.LineReader; |
| |
| import java.io.IOException; |
| import java.net.URI; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| public class RoundRobinUserResolver implements UserResolver { |
| public static final Log LOG = LogFactory.getLog(RoundRobinUserResolver.class); |
| |
| private int uidx = 0; |
| private List<UserGroupInformation> users = Collections.emptyList(); |
| |
| /** |
| * Mapping between user names of original cluster and UGIs of proxy users of |
| * simulated cluster |
| */ |
| private final HashMap<String,UserGroupInformation> usercache = |
| new HashMap<String,UserGroupInformation>(); |
| |
| /** |
| * Userlist assumes one user per line. |
| * Each line in users-list-file is of the form <username>[,group]* |
| * <br> Group names are ignored(they are not parsed at all). |
| */ |
| private List<UserGroupInformation> parseUserList(URI userUri, |
| Configuration conf) |
| throws IOException { |
| if (null == userUri) { |
| return Collections.emptyList(); |
| } |
| |
| final Path userloc = new Path(userUri.toString()); |
| final Text rawUgi = new Text(); |
| final FileSystem fs = userloc.getFileSystem(conf); |
| final ArrayList<UserGroupInformation> ugiList = |
| new ArrayList<UserGroupInformation>(); |
| |
| LineReader in = null; |
| try { |
| in = new LineReader(fs.open(userloc)); |
| while (in.readLine(rawUgi) > 0) {//line is of the form username[,group]* |
| if(rawUgi.toString().trim().equals("")) { |
| continue; //Continue on empty line |
| } |
| // e is end position of user name in this line |
| int e = rawUgi.find(","); |
| if (e == 0) { |
| throw new IOException("Missing username: " + rawUgi); |
| } |
| if (e == -1) { |
| e = rawUgi.getLength(); |
| } |
| final String username = Text.decode(rawUgi.getBytes(), 0, e).trim(); |
| UserGroupInformation ugi = null; |
| try { |
| ugi = UserGroupInformation.createProxyUser(username, |
| UserGroupInformation.getLoginUser()); |
| } catch (IOException ioe) { |
| LOG.error("Error while creating a proxy user " ,ioe); |
| } |
| if (ugi != null) { |
| ugiList.add(ugi); |
| } |
| // No need to parse groups, even if they exist. Go to next line |
| } |
| } finally { |
| if (in != null) { |
| in.close(); |
| } |
| } |
| return ugiList; |
| } |
| |
| @Override |
| public synchronized boolean setTargetUsers(URI userloc, Configuration conf) |
| throws IOException { |
| uidx = 0; |
| users = parseUserList(userloc, conf); |
| if (users.size() == 0) { |
| throw new IOException(buildEmptyUsersErrorMsg(userloc)); |
| } |
| usercache.clear(); |
| return true; |
| } |
| |
| static String buildEmptyUsersErrorMsg(URI userloc) { |
| return "Empty user list is not allowed for RoundRobinUserResolver. Provided" |
| + " user resource URI '" + userloc + "' resulted in an empty user list."; |
| } |
| |
| @Override |
| public synchronized UserGroupInformation getTargetUgi( |
| UserGroupInformation ugi) { |
| // UGI of proxy user |
| UserGroupInformation targetUGI = usercache.get(ugi.getUserName()); |
| if (targetUGI == null) { |
| targetUGI = users.get(uidx++ % users.size()); |
| usercache.put(ugi.getUserName(), targetUGI); |
| } |
| return targetUGI; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * {@link RoundRobinUserResolver} needs to map the users in the |
| * trace to the provided list of target users. So user list is needed. |
| */ |
| public boolean needsTargetUsersList() { |
| return true; |
| } |
| } |