Why is PyMongo 3 giving ServerSelectionTimeoutError?

Question

I\'m using:

• Python 3.4.2
• PyMongo 3.0.2
• mongolab running mongod 2.6.9
• uWSGI 2.0.10
• CherryPy 3.7.0
• nginx 1.6.2

Answer 1

I ran into the same issue during development. It was due to the fact that mongodb wasn't running on my local machine (sudo systemctl restart mongod to get mongodb running on Ubuntu).

Answer 2

As mentioned here: https://stackoverflow.com/a/54314615/8953378

I added ?ssl=true&ssl_cert_reqs=CERT_NONE to my connection string, and it fixed the issue.

so instead of:

connection_string = "mongodb+srv://<USER>:<PASSWORD>@<CLUSTER>/<COLLECTION>"

I wrote:

connection_string = "mongodb+srv://<USER>:<PASSWORD>@<CLUSTER>/<COLLECTION>?ssl=true&ssl_cert_reqs=CERT_NONE"

(Note that if you have other parameters in your connection string, you need to change the ? to & )