// update template_zone_ref for cross-zone template for newly added zone
  @Override
  public void associateCrosszoneTemplatesToZone(long dcId) {
    VMTemplateZoneVO tmpltZone;

    List<VMTemplateVO> allTemplates = _templateDao.listAll();
    for (VMTemplateVO vt : allTemplates) {
      if (vt.isCrossZones()) {
        tmpltZone = _vmTemplateZoneDao.findByZoneTemplate(dcId, vt.getId());
        if (tmpltZone == null) {
          VMTemplateZoneVO vmTemplateZone = new VMTemplateZoneVO(dcId, vt.getId(), new Date());
          _vmTemplateZoneDao.persist(vmTemplateZone);
        }
      }
    }
  }
 // persist entry in template_zone_ref table. zoneId can be empty for
 // region-wide image store, in that case,
 // we will associate the template to all the zones.
 @Override
 public void associateTemplateToZone(long templateId, Long zoneId) {
   List<Long> dcs = new ArrayList<Long>();
   if (zoneId != null) {
     dcs.add(zoneId);
   } else {
     List<DataCenterVO> zones = _dcDao.listAll();
     for (DataCenterVO zone : zones) {
       dcs.add(zone.getId());
     }
   }
   for (Long id : dcs) {
     VMTemplateZoneVO tmpltZoneVO = _vmTemplateZoneDao.findByZoneTemplate(id, templateId);
     if (tmpltZoneVO == null) {
       tmpltZoneVO = new VMTemplateZoneVO(id, templateId, new Date());
       _vmTemplateZoneDao.persist(tmpltZoneVO);
     } else {
       tmpltZoneVO.setLastUpdated(new Date());
       _vmTemplateZoneDao.update(tmpltZoneVO.getId(), tmpltZoneVO);
     }
   }
 }
  @Override
  public void handleTemplateSync(HostVO ssHost) {
    if (ssHost == null) {
      s_logger.warn("Huh? ssHost is null");
      return;
    }
    long sserverId = ssHost.getId();
    long zoneId = ssHost.getDataCenterId();
    if (!(ssHost.getType() == Host.Type.SecondaryStorage
        || ssHost.getType() == Host.Type.LocalSecondaryStorage)) {
      s_logger.warn("Huh? Agent id " + sserverId + " is not secondary storage host");
      return;
    }

    Map<String, TemplateInfo> templateInfos = listTemplate(ssHost);
    if (templateInfos == null) {
      return;
    }

    Set<VMTemplateVO> toBeDownloaded = new HashSet<VMTemplateVO>();
    List<VMTemplateVO> allTemplates = _templateDao.listAllInZone(zoneId);
    List<VMTemplateVO> rtngTmplts = _templateDao.listAllSystemVMTemplates();
    List<VMTemplateVO> defaultBuiltin = _templateDao.listDefaultBuiltinTemplates();

    if (rtngTmplts != null) {
      for (VMTemplateVO rtngTmplt : rtngTmplts) {
        if (!allTemplates.contains(rtngTmplt)) {
          allTemplates.add(rtngTmplt);
        }
      }
    }

    if (defaultBuiltin != null) {
      for (VMTemplateVO builtinTmplt : defaultBuiltin) {
        if (!allTemplates.contains(builtinTmplt)) {
          allTemplates.add(builtinTmplt);
        }
      }
    }

    toBeDownloaded.addAll(allTemplates);

    for (VMTemplateVO tmplt : allTemplates) {
      String uniqueName = tmplt.getUniqueName();
      VMTemplateHostVO tmpltHost = _vmTemplateHostDao.findByHostTemplate(sserverId, tmplt.getId());
      if (templateInfos.containsKey(uniqueName)) {
        TemplateInfo tmpltInfo = templateInfos.remove(uniqueName);
        toBeDownloaded.remove(tmplt);
        if (tmpltHost != null) {
          s_logger.info(
              "Template Sync found " + tmplt.getName() + " already in the template host table");
          if (tmpltHost.getDownloadState() != Status.DOWNLOADED) {
            tmpltHost.setErrorString("");
          }
          if (tmpltInfo.isCorrupted()) {
            tmpltHost.setDownloadState(Status.DOWNLOAD_ERROR);
            String msg =
                "Template "
                    + tmplt.getName()
                    + ":"
                    + tmplt.getId()
                    + " is corrupted on secondary storage "
                    + tmpltHost.getId();
            tmpltHost.setErrorString(msg);
            s_logger.info("msg");
            if (tmplt.getUrl() == null) {
              msg =
                  "Private Template ("
                      + tmplt
                      + ") with install path "
                      + tmpltInfo.getInstallPath()
                      + "is corrupted, please check in secondary storage: "
                      + tmpltHost.getHostId();
              s_logger.warn(msg);
            } else {
              toBeDownloaded.add(tmplt);
            }

          } else {
            tmpltHost.setDownloadPercent(100);
            tmpltHost.setDownloadState(Status.DOWNLOADED);
            tmpltHost.setInstallPath(tmpltInfo.getInstallPath());
            tmpltHost.setSize(tmpltInfo.getSize());
            tmpltHost.setPhysicalSize(tmpltInfo.getPhysicalSize());
            tmpltHost.setLastUpdated(new Date());

            // Skipping limit checks for SYSTEM Account and for the templates created from volumes
            // or snapshots
            // which already got checked and incremented during createTemplate API call.
            if (tmpltInfo.getSize() > 0
                && tmplt.getAccountId() != Account.ACCOUNT_ID_SYSTEM
                && tmplt.getUrl() != null) {
              long accountId = tmplt.getAccountId();
              try {
                _resourceLimitMgr.checkResourceLimit(
                    _accountMgr.getAccount(accountId),
                    com.cloud.configuration.Resource.ResourceType.secondary_storage,
                    tmpltInfo.getSize() - UriUtils.getRemoteSize(tmplt.getUrl()));
              } catch (ResourceAllocationException e) {
                s_logger.warn(e.getMessage());
                _alertMgr.sendAlert(
                    _alertMgr.ALERT_TYPE_RESOURCE_LIMIT_EXCEEDED,
                    ssHost.getDataCenterId(),
                    null,
                    e.getMessage(),
                    e.getMessage());
              } finally {
                _resourceLimitMgr.recalculateResourceCount(
                    accountId,
                    _accountMgr.getAccount(accountId).getDomainId(),
                    com.cloud.configuration.Resource.ResourceType.secondary_storage.getOrdinal());
              }
            }
          }
          _vmTemplateHostDao.update(tmpltHost.getId(), tmpltHost);
        } else {
          tmpltHost =
              new VMTemplateHostVO(
                  sserverId,
                  tmplt.getId(),
                  new Date(),
                  100,
                  Status.DOWNLOADED,
                  null,
                  null,
                  null,
                  tmpltInfo.getInstallPath(),
                  tmplt.getUrl());
          tmpltHost.setSize(tmpltInfo.getSize());
          tmpltHost.setPhysicalSize(tmpltInfo.getPhysicalSize());
          _vmTemplateHostDao.persist(tmpltHost);
          VMTemplateZoneVO tmpltZoneVO =
              _vmTemplateZoneDao.findByZoneTemplate(zoneId, tmplt.getId());
          if (tmpltZoneVO == null) {
            tmpltZoneVO = new VMTemplateZoneVO(zoneId, tmplt.getId(), new Date());
            _vmTemplateZoneDao.persist(tmpltZoneVO);
          } else {
            tmpltZoneVO.setLastUpdated(new Date());
            _vmTemplateZoneDao.update(tmpltZoneVO.getId(), tmpltZoneVO);
          }
        }

        continue;
      }
      if (tmpltHost != null && tmpltHost.getDownloadState() != Status.DOWNLOADED) {
        s_logger.info(
            "Template Sync did not find "
                + tmplt.getName()
                + " ready on server "
                + sserverId
                + ", will request download to start/resume shortly");

      } else if (tmpltHost == null) {
        s_logger.info(
            "Template Sync did not find "
                + tmplt.getName()
                + " on the server "
                + sserverId
                + ", will request download shortly");
        VMTemplateHostVO templtHost =
            new VMTemplateHostVO(
                sserverId,
                tmplt.getId(),
                new Date(),
                0,
                Status.NOT_DOWNLOADED,
                null,
                null,
                null,
                null,
                tmplt.getUrl());
        _vmTemplateHostDao.persist(templtHost);
        VMTemplateZoneVO tmpltZoneVO = _vmTemplateZoneDao.findByZoneTemplate(zoneId, tmplt.getId());
        if (tmpltZoneVO == null) {
          tmpltZoneVO = new VMTemplateZoneVO(zoneId, tmplt.getId(), new Date());
          _vmTemplateZoneDao.persist(tmpltZoneVO);
        } else {
          tmpltZoneVO.setLastUpdated(new Date());
          _vmTemplateZoneDao.update(tmpltZoneVO.getId(), tmpltZoneVO);
        }
      }
    }

    if (toBeDownloaded.size() > 0) {
      /* Only download templates whose hypervirsor type is in the zone */
      List<HypervisorType> availHypers = _clusterDao.getAvailableHypervisorInZone(zoneId);
      if (availHypers.isEmpty()) {
        /*
         * This is for cloudzone, local secondary storage resource
         * started before cluster created
         */
        availHypers.add(HypervisorType.KVM);
      }
      /* Baremetal need not to download any template */
      availHypers.remove(HypervisorType.BareMetal);
      availHypers.add(HypervisorType.None); // bug 9809: resume ISO
      // download.
      for (VMTemplateVO tmplt : toBeDownloaded) {
        if (tmplt.getUrl() == null) { // If url is null we can't
          // initiate the download
          continue;
        }
        // if this is private template, and there is no record for this
        // template in this sHost, skip
        if (!tmplt.isPublicTemplate() && !tmplt.isFeatured()) {
          VMTemplateHostVO tmpltHost =
              _vmTemplateHostDao.findByHostTemplate(sserverId, tmplt.getId());
          if (tmpltHost == null) {
            continue;
          }
        }
        if (availHypers.contains(tmplt.getHypervisorType())) {
          if (_swiftMgr.isSwiftEnabled()) {
            if (_swiftMgr.isTemplateInstalled(tmplt.getId())) {
              continue;
            }
          }
          s_logger.debug(
              "Template " + tmplt.getName() + " needs to be downloaded to " + ssHost.getName());
          downloadTemplateToStorage(tmplt, ssHost);
        } else {
          s_logger.info(
              "Skipping download of template "
                  + tmplt.getName()
                  + " since we don't have any "
                  + tmplt.getHypervisorType()
                  + " hypervisors");
        }
      }
    }

    for (String uniqueName : templateInfos.keySet()) {
      TemplateInfo tInfo = templateInfos.get(uniqueName);
      List<UserVmVO> userVmUsingIso = _userVmDao.listByIsoId(tInfo.getId());
      // check if there is any Vm using this ISO.
      if (userVmUsingIso == null || userVmUsingIso.isEmpty()) {
        DeleteTemplateCommand dtCommand =
            new DeleteTemplateCommand(ssHost.getStorageUrl(), tInfo.getInstallPath());
        try {
          _agentMgr.sendToSecStorage(ssHost, dtCommand, null);
        } catch (AgentUnavailableException e) {
          String err =
              "Failed to delete "
                  + tInfo.getTemplateName()
                  + " on secondary storage "
                  + sserverId
                  + " which isn't in the database";
          s_logger.error(err);
          return;
        }

        String description =
            "Deleted template "
                + tInfo.getTemplateName()
                + " on secondary storage "
                + sserverId
                + " since it isn't in the database";
        s_logger.info(description);
      }
    }
  }