Managing servers using parallel ssh is a way old school (and powerful) technique I don't recommend doing unless using it as a transport mechanism for a config m

Managing servers using parallel ssh is a way old school (and powerful) technique I don't recommend doing unless using it as a transport mechanism for a config management tool. A company I worked at developed a custom SSH tool that would tie into your CMDB, kind of like a home rolled ansible you could use to blast commands to whole a PoP or even the whole network at the same time. The thing was insanely powerful, but using it was like wielding a machete through a delicate garden. Ansible is really great in this regard since you have the ubiquity of SSH but sane management, not some difficult to maintain shell script. At scale parallel ssh performs poorly in comparison to message queues. As mentioned elsewhere in this thread, SaltStack defaults to using ZMQ for communication which has much lower overhead than SSH (with trade offs as well).