001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.runtime.yarn.driver;
020
021import org.apache.hadoop.yarn.api.records.Container;
022import org.apache.reef.annotations.audience.DriverSide;
023import org.apache.reef.annotations.audience.Private;
024
025import javax.inject.Inject;
026import java.util.logging.Level;
027import java.util.logging.Logger;
028
029/**
030 * Default implementation of rack names formatter.
031 * Extracts rack name from host name, if possible.
032 */
033@Private
034@DriverSide
035public final class DefaultRackNameFormatter implements RackNameFormatter {
036
037  private static final Logger LOG = Logger.getLogger(DefaultRackNameFormatter.class.getName());
038
039  @Inject
040  private DefaultRackNameFormatter() {
041  }
042
043  /**
044   * @see RackNameFormatter#getRackName(Container)
045   */
046  @Override
047  public String getRackName(final Container container) {
048    final String hostName = container.getNodeId().getHost();
049
050    // the rack name comes as part of the host name, e.g.
051    // <rackName>-<hostNumber>
052    // we perform some checks just in case it doesn't
053    String rackName = null;
054    if (hostName != null) {
055      final String[] rackNameAndNumber = hostName.split("-");
056      if (rackNameAndNumber.length == 2) {
057        rackName = rackNameAndNumber[0];
058      } else {
059        LOG.log(Level.WARNING, "Could not get information from the rack name, should use the default");
060      }
061    }
062
063    return rackName;
064  }
065}