in a module :

import pymongo

mongo_client = pymongo.MongoClient()
mongo_db = mongo_client.my_db

web handler, get :
mongo_db.db['my_collection'].save(

)

Doing this on a python web server that is very lightly used and the number of sockets opened will increase and go over 1020 and cause the server to refuse new connections to the mongo database

One way to avoid this : play with max_pool_size and waitQueueMultiple with waitQueueMultiple * max_pool_size < ulimit when creating the client.

However I think that pymongo client should have closed the unused sockets / try to reuse them instead of keep opening them, even though waitQueueMultiple=None by default.

See thread :
http://stackoverflow.com/questions/20540129/ever-increasing-number-of-opened-sockets-on-python-web-server/20548601?noredirect=1#comment30861576_20548601