State isn't always isolated, and for good reason. Design and operational parameters may dictate state as part of the expected functionality. Sometimes, because

State isn't always isolated, and for good reason. Design and operational parameters may dictate state as part of the expected functionality. Sometimes, because of the stateless nature of a protocol, extra work has to be done to constantly re-evaluate an operation in progress to see if it should be terminated early or changed. Since the operation isn't stateful, some other separate component has to act as a sort of babysitter. Then you either have to have the inefficiency of repeated calls, or implement your own pseudo-stateful protocol to wait for some kind of event to be passed up to alert it of a state change. Using the same hammer for every kind of nail is dumb. And no, you don't need a database and transactions just to perform four operations and return a result. Not every transaction will be affected by a change of state in the middle of the transaction. Sometimes transactions are duplicated, or replace a result entirely, and the latest one can win. A transaction in progress can also provide data to another transaction later, and the first transaction can be paused or terminated. We don't see complex interactions like this because the databases and protocols we use have strict separations between their parts, but we don't have to do things this way. The more functionality you surrender to a database, the less flexibility you have in the future, because now your big database is the bottleneck for operations. We need more design paradigms that allow flexible operations, and protocols that can work with such operations to manage transactions by also working with state. I say we "need" this because it seems the state of the art of these systems has languished under proclamations about what we can and can't do, due to assumptions about how we must go about them, and what technology is readily available for use. But we're talking about a new protocol, so we don't have to carry the baggage of those assumptions with us.