[mateuszf]

He means multiple instances - for scaling horizontally when traffic increases.

[showkhill]

http://progrium.viewdocs.io/dokku/process-management

[dalyons]

That's still all on one machine; Dokku can't automatically schedule & distribute containers/processes across a cluster of hosts like Empire & others can. If you're doing anything non trivial you're going to outgrow one machine pretty soon :)