@Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    RequestUpdateEvent that = (RequestUpdateEvent) o;

    if (clusterName != null ? !clusterName.equals(that.clusterName) : that.clusterName != null) return false;
    if (endTime != null ? !endTime.equals(that.endTime) : that.endTime != null) return false;
    if (requestId != null ? !requestId.equals(that.requestId) : that.requestId != null) return false;
    if (progressPercent != null ? !progressPercent.equals(that.progressPercent) : that.progressPercent != null)
      return false;
    if (requestContext != null ? !requestContext.equals(that.requestContext) : that.requestContext != null)
      return false;
    if (requestStatus != that.requestStatus) return false;
    if (startTime != null ? !startTime.equals(that.startTime) : that.startTime != null) return false;
    if (userName != null ? !userName.equals(that.userName) : that.userName != null ) return false;
    return hostRoleCommands != null ? hostRoleCommands.equals(that.hostRoleCommands) : that.hostRoleCommands == null;
  }
Contains info about request update. This update will be sent to all subscribed recipients.
ambari-server/src/main/java/org/apache/ambari/server/events/RequestUpdateEvent.java