@Transactional
  ViewInstanceEntity mergeViewInstance(ViewInstanceEntity instanceEntity, ResourceTypeEntity resourceTypeEntity) {
    // create an admin resource to represent this view instance
    instanceEntity.setResource(createViewInstanceResource(resourceTypeEntity));

    return instanceDAO.merge(instanceEntity);
  }
Sync given view with data in DB. Ensures that view data in DB is updated,
all instances changes from xml config are reflected to DB

@param view                view config from xml
@param instanceDefinitions view instances from xml
@throws Exception if the view can not be synced
ambari-server/src/main/java/org/apache/ambari/server/view/ViewRegistry.java