Not sure what causes it but I get timeouts when connecting to my hosts
with Ansible > 2.4.0.0 (tested 2.4.1.0 and current 2.5.0-devel). For
some reason switching to paramiko fixes it.
Pipelining makes ansible run tasks much faster, and as of Ansible
2.0 or 2.1 or so, it now works on older hosts that have requiretty
in their sudo config[0]. Also, disable the creation of those stupid
retry files.
[0] https://github.com/ansible/ansible/pull/13200