webFsCrawlerThread = new Thread((Runnable) () -> {
                    // crawl web
                    writeTimeToSessionInfo(crawlingInfoHelper, Constants.WEB_FS_CRAWLER_START_TIME);
                    webFsIndexHelper.crawl(options.sessionId, webConfigIdList, fileConfigIdList);
                    writeTimeToSessionInfo(crawlingInfoHelper, Constants.WEB_FS_CRAWLER_END_TIME);
                }, WEB_FS_CRAWLING_PROCESS);