content: /*
   * 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.ambari.server.events;
  
  import java.util.Collection;
  
  /**
   * The {@link AlertHashInvalidationEvent} is fired when one of the
   * following conditions is met and the alerts running on an agent need to be
   * recalculated:
   * <ul>
   * <li>An alert definition changes.</li>
   * <li>A host is removed from the cluster.</li>
   * <li>A service host component is added or removed.</li>
   * </ul>
   */
  public class AlertHashInvalidationEvent extends ClusterEvent {
    /**
     * The hosts that need to be invalidated.
     */
    private final Collection<String> m_hosts;
  
    /**
     * Constructor.
     *
     * @param clusterId
     *          the ID of the cluster that the definition is in.
     * @param hosts
     *          the hosts that were invalidated.
     */
    public AlertHashInvalidationEvent(long clusterId,
        Collection<String> hosts) {
      super(AmbariEventType.ALERT_DEFINITION_HASH_INVALIDATION, clusterId);
      m_hosts = hosts;
    }
  
    /**
     * @return the hosts
     */
    public Collection<String> getHosts() {
      return m_hosts;
    }
  }
  