public void CheckRebuildTasks()
        {
            try
            {
                var ts = _rebuildRepository.Source.unCompleteRoots();

                if (ts.Any())
                {
                    Task.Factory.StartNew(() =>
                                              {
                                                  int s = 30;
                                                  string nameList = string.Empty;
                                                  ts.ToList().ForEach(
                                                      t =>
                                                      nameList += string.Format("{0}[{1}]", t.AppName, t.AppContentName));
                                                  _log.Info(string.Format("Sleep {0}s to continue {1}", s, nameList));
                                                  System.Threading.Thread.Sleep(30*1000);
                                                  ts.ToList().ForEach(t =>
                                                                          {
                                                                              var appContent =
                                                                                  _appContentRepository.GetBy(t.AppName,
                                                                                                              t.
                                                                                                                  AppContentName);
                                                                              this.ClearRebuild(appContent.Name,
                                                                                                appContent.ContentType);

                                                                              var si = new SmartIndexer(appContent,
                                                                                                        _zzkDocumentRepository,
                                                                                                        _rebuildRepository);
                                                                              si.Rebuild(t);
                                                                          });
                                              }).LogExceptions("CheckRebuildTasks");
                }
            }
            catch(Exception exc)
            {
                _log.Error("CheckRebuildTasks", exc);
            }
        }