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.
When he changes the server from Singapore to Amerstand, how does the connection change to send packets to the new location? Can the server keep the same IP, and the internet protocol automatically finds a new shortest path to the server?
He mentions towards the end that there's a load-balancer that pauses the connection while the migration occurs. When the container comes back up, the traffic is redirected to the new instance and the connection resumes.
