The job of Half-Sync and Half-Async is to distinguish between the two types of processing called asynchronous and synchronous, for the simplification of the program without hindering its performance.
The two layers intercommunicating are introduced for both asynchronous and synchronous services for the purpose of processing with a queuing layer in between.
Every concurrent system contains both asynchronous and synchronous services. To enable these services to communicate with each other, the Half-Sync/Half-Async pattern decomposes the services in the system into layers. Using the queuing layer, both these services pass messages to each other for intercommunication.
Let's see the following diagram that illustrates these design patterns:
As you can see in the preceding diagram, there are three layers--Synchronous Service Layer, Queuing Layer,...
