ServerSelectionTimeoutError after empty response from mongodb

Traceback (most recent call last):

  File "/opt/venv/lib/python2.7/site-packages/django/core/handlers/base.py", line 111, in get_response

    response = wrapped_callback(request, *callback_args, **callback_kwargs)

  File "/opt/venv/lib/python2.7/site-packages/django/views/decorators/http.py", line 41, in inner

    return func(request, *args, **kwargs)

  File "./tracker/views.py", line 238, in counters

    for document in pydb['event_url_source_all'].find({'site': int(site_id), 'url': url}):

  File "/opt/venv/lib/python2.7/site-packages/pymongo/cursor.py", line 977, in next

    if len(self.__data) or self._refresh():

  File "/opt/venv/lib/python2.7/site-packages/pymongo/cursor.py", line 902, in _refresh

    self.__read_preference))

  File "/opt/venv/lib/python2.7/site-packages/pymongo/cursor.py", line 813, in __send_message

    **kwargs)

  File "/opt/venv/lib/python2.7/site-packages/pymongo/mongo_client.py", line 728, in _send_message_with_response

    server = topology.select_server(selector)

  File "/opt/venv/lib/python2.7/site-packages/pymongo/topology.py", line 121, in select_server

    address))

  File "/opt/venv/lib/python2.7/site-packages/pymongo/topology.py", line 97, in select_servers

    self._error_message(selector))

ServerSelectionTimeoutError: No replica set members found yet 

sendto(15, "*2\r\n$3\r\nGET\r\n$54\r\n:1:6:counters:0897835589048e427cabb81b38fb66fff8409a95\r\n", 74, 0, NULL, 0) = 74

futex(0x28945a0, FUTEX_WAKE_PRIVATE, 1) = 0

recvfrom(15, "$23\r\n\200\2}q\1X\7\0\0\0twitterq\2K\0s.\r\n", 65536, 0, NULL, NULL) = 30

futex(0x28945a0, FUTEX_WAKE_PRIVATE, 1) = 0

sendto(16, "*2\r\n$3\r\nGET\r\n$54\r\n:1:6:counters:0897835589048e427cabb81b38fb66fff8409a95\r\n", 74, 0, NULL, 0) = 74

recvfrom(16, "$6\r\n\200\2}q\1.\r\n", 65536, 0, NULL, NULL) = 12

gettimeofday({1441043559, 210954}, NULL) = 0

gettimeofday({1441043559, 211032}, NULL) = 0

futex(0x27f7390, FUTEX_WAKE_PRIVATE, 1) = 1

gettimeofday({1441043559, 211087}, NULL) = 0

select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)

$ python -c "import sys; print(sys.version)"

2.7.5 (default, Jun 24 2015, 00:41:19) 

[GCC 4.8.3 20140911 (Red Hat 4.8.3-9)]

$ python -c "import pymongo; print(pymongo.version); print(pymongo.has_c())"

3.0.3

True

CentOS Linux release 7.0.1406 (Core)

Django==1.7.7

*** Starting uWSGI 2.0.8 (64bit) on [Sun Aug 30 03:19:07 2015] ***

compiled with version: 4.8.3 20140911 (Red Hat 4.8.3-9) on 28 August 2015 11:21:52

os: Linux-3.10.0-123.8.1.el7.x86_64 #1 SMP Mon Sep 22 19:06:58 UTC 2014

nodename: app-2118

machine: x86_64

clock source: unix

detected number of CPU cores: 1

current working directory: /

detected binary path: /opt/venv/bin/uwsgi

!!! no internal routing support, rebuild with pcre support !!!

chdir() to /opt/app

your processes number limit is 7699

your memory page size is 4096 bytes

 *** WARNING: you have enabled harakiri without post buffering. Slow upload could be rejected on post-unbuffered webservers *** 

detected max file descriptor number: 1024

lock engine: pthread robust mutexes

thunder lock: enabled

uwsgi socket 0 inherited INET address 127.0.0.1:5001 fd 9

Python version: 2.7.5 (default, Jun 24 2015, 00:41:19)  [GCC 4.8.3 20140911 (Red Hat 4.8.3-9)]

Set PythonHome to /opt/venv

*** Python threads support is disabled. You can enable it with --enable-threads ***

Python main interpreter initialized at 0x1c17c20

your server socket listen backlog is limited to 100 connections

your mercy for graceful operations on workers is 60 seconds

mapped 509320 bytes (497 KB) for 6 cores

*** Operational MODE: preforking ***

WSGI app 0 (mountpoint='') ready in 0 seconds on interpreter 0x1c17c20 pid: 10057 (default app)

*** uWSGI is running in multiple interpreter mode ***

gracefully (RE)spawned uWSGI master process (pid: 10057)

sendmsg(): Transport endpoint is already connected [core/notify.c line 39]

spawned uWSGI worker 1 (pid: 15801, cores: 1)

spawned uWSGI worker 2 (pid: 15802, cores: 1)

spawned uWSGI worker 3 (pid: 15803, cores: 1)

spawned uWSGI worker 4 (pid: 15804, cores: 1)

spawned uWSGI worker 5 (pid: 15805, cores: 1)

spawned uWSGI worker 6 (pid: 15806, cores: 1)