@Subscribe
  public void onAlertStateChangeEvent(AggregateAlertRecalculateEvent event) {
    LOG.debug("Received event {}", event);

    List<String> alertNames = m_aggregateMapping.getAlertsWithAggregates(event.getClusterId());
    for (String alertName : alertNames) {
      onAlertEvent(event.getClusterId(), alertName);
    }
  }
Consumes an {@link AggregateAlertRecalculateEvent}. When a component is
removed, there may be alerts that were removed which have aggregate alerts
associated with this. This will ensure that all aggregates recalculate. It
can also be used at any point to recalculate all of the aggregates for a
cluster.
ambari-server/src/main/java/org/apache/ambari/server/events/listeners/alerts/AlertAggregateListener.java