crawler2.getCrawlerContext().setNumOfThread(numOfThread);

            final String sessionId1 = crawler1.execute();
            final String sessionId2 = crawler2.execute();

            assertNotSame(sessionId1, sessionId2);
            assertNotSame(crawler1.crawlerContext, crawler2.crawlerContext);

            Thread.sleep(1000);

        }
    }

    @Override
    public void delete(final String sessionId) {
        deleteBySessionId(sessionId);
    }

    @Override
    public void offerAll(final String sessionId, final List<OpenSearchUrlQueue> urlQueueList) {
        if (logger.isDebugEnabled()) {
            logger.debug("Offering URL: Session ID: {}, UrlQueue: {}", sessionId, urlQueueList);
        }

            crawler2.getCrawlerContext().setNumOfThread(numOfThread);

            final String sessionId1 = crawler1.execute();
            final String sessionId2 = crawler2.execute();

            assertNotSame(sessionId1, sessionId2);
            assertNotSame(crawler1.crawlerContext, crawler2.crawlerContext);

            Thread.sleep(1000);

        final Object sessionId = sessionIdProp.getValue(target);
        return sessionId == null ? null : sessionId.toString();
    }

    private String getSessionId(final Object target) {
        final BeanDesc beanDesc = BeanDescFactory.getBeanDesc(target.getClass());
        final PropertyDesc sessionIdProp = beanDesc.getPropertyDesc(SESSION_ID);
        final Object sessionId = sessionIdProp.getValue(target);

    public String getCanonicalSessionId(final String sessionId) {
        final int idx = sessionId.indexOf('-');
        if (idx >= 0) {
            return sessionId.substring(0, idx);
        }
        return sessionId;
    }

    public synchronized void store(final String sessionId, final boolean create) {
        CrawlingInfo crawlingInfo = create ? null : getCrawlingInfoService().getLast(sessionId);
        if (crawlingInfo == null) {

        if (StringUtil.isBlank(options.sessionId)) {
            // use a default session id
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
            options.sessionId = sdf.format(new Date());
        } else {
            options.sessionId = options.sessionId.replace('-', '_');
        }

        if (StringUtil.isNotBlank(crawlingInfoPager.sessionId)) {
            cb.query().setSessionId_Match(crawlingInfoPager.sessionId);
        }
        cb.query().addOrderBy_CreatedTime_Desc();
    }

    protected void setupStoreCondition(final CrawlingInfo crawlingInfo) {
        if (crawlingInfo == null) {
            throw new FessSystemException("Crawling Session is null.");
        }

        TermQueryBuilder builder = regTermQ("sessionId", sessionId);
        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

    public void setSessionId_NotEqual(String sessionId) {
        setSessionId_NotTerm(sessionId, null);
    }

    public void setSessionId_NotTerm(String sessionId) {
        setSessionId_NotTerm(sessionId, null);

        }
        try {
            urlQueueService.delete(sessionId);
        } catch (final Exception e) {
            logger.warn("Failed to delete url queues: {}", sessionId, e);
        }
        try {
            dataService.delete(sessionId);
        } catch (final Exception e) {
            logger.warn("Failed to delete data: {}", sessionId, e);
        }
    }

    @Override

        if (sessionId == null) { // create session id
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
            sessionId = sdf.format(new Date());
        }
        resultBuf.append("Session Id: ").append(sessionId).append("\n");
        resultBuf.append("Web  Config Id:");
        if (webConfigIds == null) {