apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/AdminService.java/AdminService/createNewApp
class AdminService:  @Transactional
  public App createNewApp(App app) {
    String createBy = app.getDataChangeCreatedBy();
    App createdApp = appService.save(app);

    String appId = createdApp.getAppId();

    appNamespaceService.createDefaultAppNamespace(appId, createBy);

    clusterService.createDefaultCluster(appId, createBy);

    namespaceService.instanceOfAppNamespaces(appId, ConfigConsts.CLUSTER_NAME_DEFAULT, createBy);

    return app;
  }