@Override
  public void setHostRequestStatus(long hostRequestId, HostRoleStatus status, String message) {
    TopologyHostRequestEntity hostRequestEntity = hostRequestDAO.findById(hostRequestId);
    if (hostRequestEntity != null) {
      hostRequestEntity.setStatus(status);
      hostRequestEntity.setStatusMessage(message);
      hostRequestDAO.merge(hostRequestEntity);
    }
  }
Implementation which uses Ambari Database DAO and Entity objects for persistence
of topology related information.
ambari-server/src/main/java/org/apache/ambari/server/topology/PersistedStateImpl.java