Hello! I use pymongo and:

conn = MongoReplicaSetClient('localhost:27018', replicaSet='test_rs', journal=True, slave_okay=True)

In replica set test_rs i have three members. When i shutdown (i mean completly shutdown - like shutdown -h command) one server from this replica set - i have very slow connection (timeout about ten seconds).

I found work around in PHP thread. If i use connectTimeoutMS=200 parametr - i have delay only 200ms in my case. For example:

conn = MongoReplicaSetClient('localhost:27018', replicaSet='test_rs', journal=True, connectTimeoutMS=200, slave_okay=True)

This bug - the same as in PHP: https://jira.mongodb.org/browse/PHP-651

Discussion about this bug in PHP:
https://groups.google.com/forum/?fromgroups=#!topic/mongodb-user/yXteb2pX3j8