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.listeners.alerts;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.ambari.server.EagerSingleton;
  import org.apache.ambari.server.api.query.render.AlertSummaryGroupedRenderer;
  import org.apache.ambari.server.events.AggregateAlertRecalculateEvent;
  import org.apache.ambari.server.events.AlertEvent;
  import org.apache.ambari.server.events.AlertUpdateEvent;
  import org.apache.ambari.server.events.MaintenanceModeEvent;
  import org.apache.ambari.server.events.publishers.AlertEventPublisher;
  import org.apache.ambari.server.events.publishers.AmbariEventPublisher;
  import org.apache.ambari.server.events.publishers.STOMPUpdatePublisher;
  import org.apache.ambari.server.orm.dao.AlertsDAO;
  import org.apache.ambari.server.orm.entities.AlertCurrentEntity;
  import org.apache.ambari.server.orm.entities.AlertDefinitionEntity;
  import org.apache.ambari.server.orm.entities.AlertHistoryEntity;
  import org.apache.ambari.server.orm.entities.AlertNoticeEntity;
  import org.apache.ambari.server.state.AlertState;
  import org.apache.ambari.server.state.Host;
  import org.apache.ambari.server.state.MaintenanceState;
  import org.apache.ambari.server.state.Service;
  import org.apache.ambari.server.state.ServiceComponentHost;
  import org.apache.ambari.server.state.alert.AggregateDefinitionMapping;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.common.eventbus.AllowConcurrentEvents;
  import com.google.common.eventbus.Subscribe;
  import com.google.inject.Inject;
  import com.google.inject.Singleton;
  
  /**
   * The {@link AlertMaintenanceModeListener} handles events that relate to
   * Maintenance Mode changes.
   */
  @Singleton
  @EagerSingleton
  public class AlertMaintenanceModeListener {
    /**
     * Logger.
     */
    private static final Logger LOG = LoggerFactory.getLogger(AlertMaintenanceModeListener.class);
  
    /**
     * Publishes {@link AlertEvent} instances.
     */
    @Inject
    private AlertEventPublisher m_alertEventPublisher;
  
    /**
     * Used for updating the MM of current alerts.
     */
    @Inject
    private AlertsDAO m_alertsDao = null;
  
    /**
     * Used for quick lookups of aggregate alerts.
     */
    @Inject
    private AggregateDefinitionMapping m_aggregateMapping;
  
    @Inject
    private STOMPUpdatePublisher  STOMPUpdatePublisher;
  
    private long clusterId = -1;
  
    /**
     * Constructor.
     *
     * @param publisher
     */
    @Inject
    public AlertMaintenanceModeListener(AmbariEventPublisher publisher) {
      publisher.register(this);
    }
  
    /**
     * Handles {@link MaintenanceModeEvent} by performing the following tasks:
     * <ul>
     * <li>Iterates through all {@link AlertNoticeEntity}, updating the MM state</li>
     * </ul>
     *
     * @param event
     *          the event being handled.
     */
    @Subscribe
    @AllowConcurrentEvents
    public void onEvent(MaintenanceModeEvent event) {
      LOG.debug("Received event {}", event);
  
      boolean recalculateAggregateAlert = false;
      List<AlertCurrentEntity> currentAlerts = m_alertsDao.findCurrent();
  
      MaintenanceState newMaintenanceState = MaintenanceState.OFF;
      if (event.getMaintenanceState() != MaintenanceState.OFF) {
        newMaintenanceState = MaintenanceState.ON;
      }
      Map<Long, Map<String, AlertSummaryGroupedRenderer.AlertDefinitionSummary>> alertUpdates = new HashMap<>();
      for( AlertCurrentEntity currentAlert : currentAlerts ){
        AlertHistoryEntity history = currentAlert.getAlertHistory();
  
        String alertHostName = history.getHostName();
        String alertServiceName = history.getServiceName();
        String alertComponentName = history.getComponentName();
  
        try {
          Host host = event.getHost();
          Service service = event.getService();
          ServiceComponentHost serviceComponentHost = event.getServiceComponentHost();
  
          // host level maintenance
          if( null != host ){
            String hostName = host.getHostName();
            if( hostName.equals( alertHostName ) ){
              if (updateMaintenanceStateAndRecalculateAggregateAlert(history, currentAlert, newMaintenanceState, alertUpdates))
                recalculateAggregateAlert = true;
              continue;
            }
          } else if( null != service ){
            // service level maintenance
            String serviceName = service.getName();
            if( serviceName.equals(alertServiceName)){
              if (updateMaintenanceStateAndRecalculateAggregateAlert(history, currentAlert, newMaintenanceState, alertUpdates))
                recalculateAggregateAlert = true;
              continue;
            }
          } else if( null != serviceComponentHost ){
            // component level maintenance
            String hostName = serviceComponentHost.getHostName();
            String serviceName = serviceComponentHost.getServiceName();
            String componentName = serviceComponentHost.getServiceComponentName();
  
            // match on all 3 for a service component
            if (hostName.equals(alertHostName) && serviceName.equals(alertServiceName)
                && componentName.equals(alertComponentName)) {
              if (updateMaintenanceStateAndRecalculateAggregateAlert(history, currentAlert, newMaintenanceState, alertUpdates))
                recalculateAggregateAlert = true;
              continue;
            }
          }
        } catch (Exception exception) {
          AlertDefinitionEntity definition = history.getAlertDefinition();
          LOG.error("Unable to put alert '{}' for host {} into maintenance mode",
              definition.getDefinitionName(), alertHostName, exception);
        }
      }
  
      if (!alertUpdates.isEmpty()) {
        STOMPUpdatePublisher.publish(new AlertUpdateEvent(alertUpdates));
      }
  
      if (recalculateAggregateAlert) {
        // publish the event to recalculate aggregates
        m_alertEventPublisher.publish(new AggregateAlertRecalculateEvent(clusterId));
      }
    }
  
    /**
     * Updates the maintenance state of the specified alert if different than the
     * supplied maintenance state. And recalcualte aggregates if the maintenance state
     * is changed and there is an aggregate alert for the specified alert if it is
     * in CRITICAL or WARNING state.
     *
     * @param historyAlert
     *          the alert to check if having an aggregate alert associated with it.
     * @param currentAlert
     *          the alert to update (not {@code null}).
     * @param maintenanceState
     *          the maintenance state to change to, either
     *          {@link MaintenanceState#OFF} or {@link MaintenanceState#ON}.
     */
    private boolean updateMaintenanceStateAndRecalculateAggregateAlert (AlertHistoryEntity historyAlert,
        AlertCurrentEntity currentAlert, MaintenanceState maintenanceState, Map<Long, Map<String,
        AlertSummaryGroupedRenderer.AlertDefinitionSummary>> alertUpdates) {
  
      AlertDefinitionEntity definitionEntity = currentAlert.getAlertHistory().getAlertDefinition();
      // alerts only care about OFF or ON
      if (maintenanceState != MaintenanceState.OFF && maintenanceState != MaintenanceState.ON) {
        LOG.warn("Unable to set invalid maintenance state of {} on the alert {}", maintenanceState,
            definitionEntity.getDefinitionName());
  
        return false;
      }
  
      MaintenanceState currentState = currentAlert.getMaintenanceState();
      if (currentState == maintenanceState) {
        return false;
      }
  
      currentAlert.setMaintenanceState(maintenanceState);
      m_alertsDao.merge(currentAlert);
  
      AlertState alertState = historyAlert.getAlertState();
  
      if (!alertUpdates.containsKey(historyAlert.getClusterId())) {
        alertUpdates.put(historyAlert.getClusterId(), new HashMap<>());
      }
      Map<String, AlertSummaryGroupedRenderer.AlertDefinitionSummary> summaries = alertUpdates.get(historyAlert.getClusterId());
  
      // alert history doesn't change when MM is turned on/off, so timestamp and text should be empty
      AlertSummaryGroupedRenderer.updateSummary(summaries, definitionEntity.getDefinitionId(),
          definitionEntity.getDefinitionName(), alertState, -1L, maintenanceState, "");
  
      if (AlertState.RECALCULATE_AGGREGATE_ALERT_STATES.contains(alertState)){
        clusterId = historyAlert.getClusterId();
        String alertName = historyAlert.getAlertDefinition().getDefinitionName();
  
        if (m_aggregateMapping.getAggregateDefinition(clusterId, alertName) != null){
          return true;
        }
      }
      return false;
    }
  }
  