text: /*
   * 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.ignite.events;
  
  import java.util.Collection;
  import org.apache.ignite.IgniteEvents;
  import org.apache.ignite.cluster.BaselineNode;
  import org.apache.ignite.cluster.ClusterNode;
  import org.apache.ignite.configuration.IgniteConfiguration;
  import org.apache.ignite.lang.IgnitePredicate;
  import org.jetbrains.annotations.Nullable;
  
  /**
   * Cluster activation event.
   * <p>
   * Grid events are used for notification about what happens within the grid. Note that by
   * design Ignite keeps all events generated on the local node locally and it provides
   * APIs for performing a distributed queries across multiple nodes:
   * <ul>
   *      <li>
   *          {@link IgniteEvents#remoteQuery(IgnitePredicate, long, int...)} -
   *          asynchronously querying events occurred on the nodes specified, including remote nodes.
   *      </li>
   *      <li>
   *          {@link IgniteEvents#localQuery(IgnitePredicate, int...)} -
   *          querying only local events stored on this local node.
   *      </li>
   *      <li>
   *          {@link IgniteEvents#localListen(IgnitePredicate, int...)} -
   *          listening to local grid events (events from remote nodes not included).
   *      </li>
   * </ul>
   * User can also wait for events using method {@link IgniteEvents#waitForLocal(IgnitePredicate, int...)}.
   * <h1 class="header">Events and Performance</h1>
   * Note that by default all events in Ignite are enabled and therefore generated and stored
   * by whatever event storage SPI is configured. Ignite can and often does generate thousands events per seconds
   * under the load and therefore it creates a significant additional load on the system. If these events are
   * not needed by the application this load is unnecessary and leads to significant performance degradation.
   * <p>
   * It is <b>highly recommended</b> to enable only those events that your application logic requires
   * by using {@link IgniteConfiguration#getIncludeEventTypes()} method in Ignite configuration. Note that certain
   * events are required for Ignite's internal operations and such events will still be generated but not stored by
   * event storage SPI if they are disabled in Ignite configuration.
   * @see EventType#EVT_CLUSTER_ACTIVATED
   * @see EventType#EVT_CLUSTER_DEACTIVATED
   * @deprecated Use {@link ClusterStateChangeEvent} instead.
   */
  @Deprecated
  public class ClusterActivationEvent extends EventAdapter {
      /** */
      private static final long serialVersionUID = 0L;
  
      /** Baseline nodes. */
      private final Collection<BaselineNode> baselineNodes;
  
      /**
       * Creates activation event with given parameters.
       *
       * @param node Node.
       * @param msg Optional event message.
       * @param type Event type.
       * @param baselineNodes Baseline nodes.
       */
      public ClusterActivationEvent(ClusterNode node, String msg, int type, Collection<BaselineNode> baselineNodes) {
          super(node, msg, type);
  
          assert baselineNodes != null;
  
          this.baselineNodes = baselineNodes;
      }
  
      /**
       * Gets baseline nodes.
       *
       * @return Baseline nodes.
       */
      public @Nullable Collection<BaselineNode> baselineNodes() {
          return baselineNodes;
      }
  }
  