<a href="https://youtu.be/mL9AFkJJAq0?t=27m30s" rel="nofollow">https://youtu.be/mL9AFkJJAq0?t=27m30s</a> if you want to see the actual demo...
They are running docket instances in all the data centers at the same time. each time he migrates the running instance, he pauses the instance, saves the contents of the instances ram and file descriptors (checkpoint), moves or copies that checkpoint to another data center, changes iptables to redirect any clients to the new instance through the load balancer and starts the instance in the new location. all scripted of course. Pure devops. This is basically how a love migration works on all hypervisors but it is really cool to see it in docker.
Doesn't this go against the 'cattle not pets' philosophy? Even though they're just moving RAM, it gives you the impression of permanence of a given state.
Slick! In the next generation of phones (I.e. ones with more ram) I could easily see coming home and flicking my wrist to "throw" a VM off my phone to a local VM server. What application does that fit? No idea. It just sounds like fun.