diff --git a/CHANGELOG.md b/CHANGELOG.md
index 70cd6e83..7c81377a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,6 @@
 ### Features / Enhancement
 - **Documentation**: Better and much more detailed documentation.
 - **Better Crontab**: Make crontab expression through crontab UI.
-- **High Concurrency**: `gevent` + `flask` to support high concurrency. [#70](https://github.com/tikazyq/crawlab/issues/70)
 
 ### Bugs Fixes
 - **Deleting Spider**. Deleting a spider does not only remove record in db but also removing related folder, tasks and schedules. [#69](https://github.com/tikazyq/crawlab/issues/69)
diff --git a/Jenkinsfile b/Jenkinsfile
index 9c893e51..b22488cc 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -37,7 +37,7 @@ pipeline {
             steps {
                 echo 'Deploying....'
                 sh """
-                docker stop crawlab | true
+                docker rm -f crawlab | true
                 docker run -d --rm --name crawlab \
                     -p 8080:8080 \
                     -p 8000:8000 \
diff --git a/spiders/example_juejin/juejin/__init__.py b/spiders/example_juejin/juejin/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/spiders/example_juejin/juejin/items.py b/spiders/example_juejin/juejin/items.py
deleted file mode 100644
index 2c4717dd..00000000
--- a/spiders/example_juejin/juejin/items.py
+++ /dev/null
@@ -1,17 +0,0 @@
-# -*- coding: utf-8 -*-
-
-# Define here the models for your scraped items
-#
-# See documentation in:
-# http://doc.scrapy.org/en/latest/topics/items.html
-
-import scrapy
-
-
-class JuejinItem(scrapy.Item):
-    # define the fields for your item here like:
-    _id = scrapy.Field()
-    title = scrapy.Field()
-    link = scrapy.Field()
-    like = scrapy.Field()
-    task_id = scrapy.Field()
diff --git a/spiders/example_juejin/juejin/middlewares.py b/spiders/example_juejin/juejin/middlewares.py
deleted file mode 100644
index 9d5225a2..00000000
--- a/spiders/example_juejin/juejin/middlewares.py
+++ /dev/null
@@ -1,56 +0,0 @@
-# -*- coding: utf-8 -*-
-
-# Define here the models for your spider middleware
-#
-# See documentation in:
-# http://doc.scrapy.org/en/latest/topics/spider-middleware.html
-
-from scrapy import signals
-
-
-class JuejinSpiderMiddleware(object):
-    # Not all methods need to be defined. If a method is not defined,
-    # scrapy acts as if the spider middleware does not modify the
-    # passed objects.
-
-    @classmethod
-    def from_crawler(cls, crawler):
-        # This method is used by Scrapy to create your spiders.
-        s = cls()
-        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
-        return s
-
-    def process_spider_input(self, response, spider):
-        # Called for each response that goes through the spider
-        # middleware and into the spider.
-
-        # Should return None or raise an exception.
-        return None
-
-    def process_spider_output(self, response, result, spider):
-        # Called with the results returned from the Spider, after
-        # it has processed the response.
-
-        # Must return an iterable of Request, dict or Item objects.
-        for i in result:
-            yield i
-
-    def process_spider_exception(self, response, exception, spider):
-        # Called when a spider or process_spider_input() method
-        # (from other spider middleware) raises an exception.
-
-        # Should return either None or an iterable of Response, dict
-        # or Item objects.
-        pass
-
-    def process_start_requests(self, start_requests, spider):
-        # Called with the start requests of the spider, and works
-        # similarly to the process_spider_output() method, except
-        # that it doesn’t have a response associated.
-
-        # Must return only requests (not items).
-        for r in start_requests:
-            yield r
-
-    def spider_opened(self, spider):
-        spider.logger.info('Spider opened: %s' % spider.name)
diff --git a/spiders/example_juejin/juejin/pipelines.py b/spiders/example_juejin/juejin/pipelines.py
deleted file mode 100644
index 1c4ffdc1..00000000
--- a/spiders/example_juejin/juejin/pipelines.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# -*- coding: utf-8 -*-
-
-# Define your item pipelines here
-#
-# Don't forget to add your pipeline to the ITEM_PIPELINES setting
-# See: http://doc.scrapy.org/en/latest/topics/item-pipeline.html
-import os
-
-from pymongo import MongoClient
-
-MONGO_HOST = os.environ['MONGO_HOST']
-MONGO_PORT = int(os.environ['MONGO_PORT'])
-MONGO_DB = os.environ['MONGO_DB']
-
-
-class JuejinPipeline(object):
-    mongo = MongoClient(host=MONGO_HOST, port=MONGO_PORT)
-    db = mongo[MONGO_DB]
-    col_name = os.environ.get('CRAWLAB_COLLECTION','test')
-    col = db[col_name]
-
-    def process_item(self, item, spider):
-        item['task_id'] = os.environ.get('CRAWLAB_TASK_ID')
-        self.col.save(item)
-        return item
diff --git a/spiders/example_juejin/juejin/settings.py b/spiders/example_juejin/juejin/settings.py
deleted file mode 100644
index 44f8866c..00000000
--- a/spiders/example_juejin/juejin/settings.py
+++ /dev/null
@@ -1,89 +0,0 @@
-# -*- coding: utf-8 -*-
-
-# Scrapy settings for juejin project
-#
-# For simplicity, this file contains only settings considered important or
-# commonly used. You can find more settings consulting the documentation:
-#
-#     http://doc.scrapy.org/en/latest/topics/settings.html
-#     http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
-#     http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
-
-BOT_NAME = 'juejin'
-
-SPIDER_MODULES = ['juejin.spiders']
-NEWSPIDER_MODULE = 'juejin.spiders'
-
-# Crawl responsibly by identifying yourself (and your website) on the user-agent
-USER_AGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
-
-# Obey robots.txt rules
-ROBOTSTXT_OBEY = True
-
-# Configure maximum concurrent requests performed by Scrapy (default: 16)
-# CONCURRENT_REQUESTS = 32
-
-# Configure a delay for requests for the same website (default: 0)
-# See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay
-# See also autothrottle settings and docs
-# DOWNLOAD_DELAY = 3
-# The download delay setting will honor only one of:
-# CONCURRENT_REQUESTS_PER_DOMAIN = 16
-# CONCURRENT_REQUESTS_PER_IP = 16
-
-# Disable cookies (enabled by default)
-# COOKIES_ENABLED = False
-
-# Disable Telnet Console (enabled by default)
-# TELNETCONSOLE_ENABLED = False
-
-# Override the default request headers:
-# DEFAULT_REQUEST_HEADERS = {
-#   'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
-#   'Accept-Language': 'en',
-# }
-
-# Enable or disable spider middlewares
-# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
-# SPIDER_MIDDLEWARES = {
-#    'juejin.middlewares.JuejinSpiderMiddleware': 543,
-# }
-
-# Enable or disable downloader middlewares
-# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
-# DOWNLOADER_MIDDLEWARES = {
-#    'juejin.middlewares.MyCustomDownloaderMiddleware': 543,
-# }
-
-# Enable or disable extensions
-# See http://scrapy.readthedocs.org/en/latest/topics/extensions.html
-# EXTENSIONS = {
-#    'scrapy.extensions.telnet.TelnetConsole': None,
-# }
-
-# Configure item pipelines
-# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
-ITEM_PIPELINES = {
-    'juejin.pipelines.JuejinPipeline': 300,
-}
-
-# Enable and configure the AutoThrottle extension (disabled by default)
-# See http://doc.scrapy.org/en/latest/topics/autothrottle.html
-# AUTOTHROTTLE_ENABLED = True
-# The initial download delay
-# AUTOTHROTTLE_START_DELAY = 5
-# The maximum download delay to be set in case of high latencies
-# AUTOTHROTTLE_MAX_DELAY = 60
-# The average number of requests Scrapy should be sending in parallel to
-# each remote server
-# AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
-# Enable showing throttling stats for every response received:
-# AUTOTHROTTLE_DEBUG = False
-
-# Enable and configure HTTP caching (disabled by default)
-# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
-# HTTPCACHE_ENABLED = True
-# HTTPCACHE_EXPIRATION_SECS = 0
-# HTTPCACHE_DIR = 'httpcache'
-# HTTPCACHE_IGNORE_HTTP_CODES = []
-# HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'
diff --git a/spiders/example_juejin/juejin/spiders/__init__.py b/spiders/example_juejin/juejin/spiders/__init__.py
deleted file mode 100644
index ebd689ac..00000000
--- a/spiders/example_juejin/juejin/spiders/__init__.py
+++ /dev/null
@@ -1,4 +0,0 @@
-# This package will contain the spiders of your Scrapy project
-#
-# Please refer to the documentation for information on how to create and manage
-# your spiders.
diff --git a/spiders/example_juejin/juejin/spiders/juejin_spider.py b/spiders/example_juejin/juejin/spiders/juejin_spider.py
deleted file mode 100644
index 28df5be7..00000000
--- a/spiders/example_juejin/juejin/spiders/juejin_spider.py
+++ /dev/null
@@ -1,17 +0,0 @@
-# -*- coding: utf-8 -*-
-import scrapy
-from juejin.items import JuejinItem
-
-
-class JuejinSpiderSpider(scrapy.Spider):
-    name = 'juejin_spider'
-    allowed_domains = ['juejin.com']
-    start_urls = ['https://juejin.im/search?query=celery']
-
-    def parse(self, response):
-        for item in response.css('ul.main-list > li.item'):
-            yield JuejinItem(
-                title=item.css('.title span').extract_first(),
-                link=item.css('a::attr("href")').extract_first(),
-                like=item.css('.like .count::text').extract_first(),
-            )
diff --git a/spiders/example_juejin/scrapy.cfg b/spiders/example_juejin/scrapy.cfg
deleted file mode 100644
index 38ba44f1..00000000
--- a/spiders/example_juejin/scrapy.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Automatically created by: scrapy startproject
-#
-# For more information about the [deploy] section see:
-# https://scrapyd.readthedocs.org/en/latest/deploy.html
-
-[settings]
-default = juejin.settings
-
-[deploy]
-#url = http://localhost:6800/
-project = juejin
diff --git a/spiders/example_juejin/start.py b/spiders/example_juejin/start.py
deleted file mode 100644
index ec2f47dd..00000000
--- a/spiders/example_juejin/start.py
+++ /dev/null
@@ -1,2 +0,0 @@
-from scrapy import cmdline
-cmdline.execute(["scrapy","crawl","juejin_spider"])
\ No newline at end of file