code: @Override
      @Transactional
      public void cancelSnapshot(String snapshotId) throws SnapshotException {
          checkInitialized();
          final Snapshot snapshot = getSnapshot(snapshotId);
          stop(snapshot);
          String snapshotDir = ContentDirUtils.getDestinationPath(snapshotId, this.config.getContentRootDir());
          deleteDirectory(snapshotDir);
  
          new Thread(new Runnable() {
              @Override
              public void run() {
                  final DuracloudEndPointConfig source = snapshot.getSource();
                  final String spaceId = source.getSpaceId();
                  final ContentStore contentStore =
                      storeClientHelper.create(source,
                                               config.getDuracloudUsername(),
                                               config.getDuracloudPassword());
                  try {
                      String result = new Retrier().execute(new Retriable() {
                          /* (non-Javadoc)
                           * @see org.duracloud.common.retry.Retriable#retry()
                           */
                          @Override
                          public Object retry() throws Exception {
                              CompleteCancelSnapshotTaskParameters params =
                                  new CompleteCancelSnapshotTaskParameters();
                              params.setSpaceId(spaceId);
                              return contentStore.performTask(SnapshotConstants.COMPLETE_SNAPSHOT_CANCEL_TASK_NAME,
                                                              params.serialize());
                          }
                      });
  
                      log.info("snapshot cancellation is complete: {}", result);
  
                      snapshot.setStatus(SnapshotStatus.CANCELLED);
                      snapshot.setStatusText("");
                      eventLog.logSnapshotUpdate(snapshot);
                  } catch (Exception ex) {
                      log.error("failed to complete cancellation on the durastore side for space {}:  {}",
                                spaceId,
                                ex.getMessage(),
                                ex);
                  }
  
              }
          }).start();
      }
docs: /*
  (non-Javadoc)
  
  @see
  org.duracloud.snapshot.service.SnapshotJobManager#cancelSnapshot(java.
  lang.String)