折腾：
【未解决】在线环境中用gunicorn部署的产品demo无法正常初始化运行
期间，发现Flask的app还是无法正常运行，无法响应前端页面的请求，然后去看看log，发现了问题：
/Users/crifan/dev/xxx/logs/gunicorn_error.log
<code>[2018-08-28 11:01:13,933] INFO in qa: audioFileObjectId=5b21cc3e7f4d384d0453b763 [2018-08-28 11:01:44,060] ERROR in app: Exception on /qa [GET] Traceback (most recent call last): File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/flask/app.py", line 1813, in full_dispatch_request rv = self.dispatch_request() File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/flask/app.py", line 1799, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/flask_restful/__init__.py", line 480, in wrapper resp = resource(*args, **kwargs) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/flask/views.py", line 88, in view return self.dispatch_request(*args, **kwargs) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/flask_restful/__init__.py", line 595, in dispatch_request resp = meth(*args, **kwargs) File "/root/xxx/robotDemo/resources/qa.py", line 146, in get if fsCollection.exists(audioFileObjectId): File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/gridfs/__init__.py", line 406, in exists f = self.__files.find_one(document_or_id, ["_id"], session=session) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/collection.py", line 1262, in find_one for result in cursor.limit(-1): File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/cursor.py", line 1189, in next if len(self.__data) or self._refresh(): File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/cursor.py", line 1087, in _refresh self.__session = self.__collection.database.client._ensure_session() File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/mongo_client.py", line 1558, in _ensure_session return self.__start_session(True, causal_consistency=False) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/mongo_client.py", line 1511, in __start_session server_session = self._get_server_session() File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/mongo_client.py", line 1544, in _get_server_session return self._topology.get_server_session() File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/topology.py", line 427, in get_server_session None) File "/root/.local/share/virtualenvs/robotDemo-dwdcgdaG/lib/python3.6/site-packages/pymongo/topology.py", line 199, in _select_servers_loop self._error_message(selector)) pymongo.errors.ServerSelectionTimeoutError: localhost:32018: [Errno 111] Connection refused </code>
发现是mongo的gridfs连接有问题
去找找是什么原因
以为是：
mongo的port本身已经是int：
又在初始化mongo时强制转换int：
以为会出问题呢，后来测试了Python代码，是没问题的：
<code>➜ ~ python
Python 2.7.10 (default, Oct 6 2017, 22:29:07)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> print("test int and int")
test int and int
>>> alreayInt = 20
>>> convertedInt = int(20)
>>> print convertedInt
20
</code>但是看了下log中输出的服务器中本地的mongo的连接是对的：
<code>'MONGODB_AUTH_SOURCE': 'gridfs', 'MONGODB_HOST': 'localhost', 'MONGODB_PASSWORD': 'P@Wd', 'MONGODB_PORT': p, 'MONGODB_USERNAME': 'gridfs', </code>
去研究看看：
pymongo.errors.ServerSelectionTimeoutError: localhost:32018: [Errno 111] Connection refused
先去找找服务器本地，确保mongod是正常运行的：
【已解决】CentOS中如何查看Mongod的server的运行情况
然后就解决了此处的问题了：
至少后续调用，是可以正常调用mongo连接的：
【总结】
此处，不知道何故，导致之前正常的mongod的状态是active(existed)，从而不正常工作了
然后通过重启mongo：
<code>systemctl restart mongod </code>
使得状态恢复为正常的：
Active: active (running)
后，前端页面连接后端接口，内部调用到mongo的gridfs，就正常工作了。
转载请注明：在路上 » 【已解决】在线CentOS中Flask运行mongo出错：pymongo.errors.ServerSelectionTimeoutError localhost Errno 111 Connection refused