if (!client.existsIndex(indexName)) {
            return "No log notifications.";
        }

        final int searchSize = fessConfig.getLogNotificationSearchSizeAsInteger();
        final String hostname = ComponentUtil.getSystemHelper().getHostname();
        final SearchResponse searchResponse = client.prepareSearch(indexName)

     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getLogNotificationSearchSizeAsInteger();

    /**
     * Get the value for the key 'log.notification.buffer.size'. <br>
     * The value is, e.g. 1000 <br>
     * comment: Maximum number of events to buffer in memory.