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

We're investigating this problem, tracked in PYTHON-961. You may be able to work around the issue by passing connect=False when creating instances of MongoClient. That defers background connection until the first database operation is attempted, avoiding what I suspect is a race condition between spin up of MongoClient's monitor thread and multiprocess forking.