The Disruptor components are not part of a single threaded process, as far as I understand

"Also these three tasks are relatively independent, all of them need to be done before the Business Logic Processor works on a message, but they can done in any order. So unlike with the Business Logic Processor, where each trade changes the market for subsequent trades, there is a natural fit for concurrency."

I think that the Disruptor can run on the save JVM as the business logic, also to avoid remoting-related bottlenecks.