final List<LogNotificationEvent> batch = events.subList(i, Math.min(i + BATCH_SIZE, events.size()));
                final BulkRequestBuilder bulkRequest = client.prepareBulk();
                for (final LogNotificationEvent event : batch) {
                    final Map<String, Object> source = new HashMap<>();
                    source.put("hostname", hostname);

            return 0L;
        }
        final SearchEngineClient client = ComponentUtil.getSearchEngineClient();
        if (bulkRequestBuilder == null) {
            bulkRequestBuilder = client.prepareBulk();
        }
        final String index = fessConfig.getIndexDocumentUpdateIndex();
        for (final String id : ids) {
            bulkRequestBuilder.add(client.prepareUpdate()
                    .setIndex(index)

            } finally {
                SMailCallbackContext.clearPreparedMessageHookOnThread();
            }
        }

        final BulkRequestBuilder bulkDelete = client.prepareBulk();
        for (final String docId : docIds) {
            bulkDelete.add(client.prepareDelete().setIndex(indexName).setId(docId));
        }
        bulkDelete.execute().actionGet(fessConfig.getIndexSearchTimeout());