Scaling a service by itself is not sufficient. Just because you create instances of your service doesn't mean they'll just work together. There are two important steps to enable a service scale:
- Making instances work together
- Making instances reachable
Instances don't need to communicate with each other, but an instance must be able to work without interfering with the others. An instance should be able to handle a request from a client that was previously served by another instance. In our case, this means an instance must be able to manipulate an image that was uploaded by another instance. This ensures that if an instance goes offline, others can take over its clients.
Instances need to be reachable, which means ...