Why Use Asynchronous Communication?
SAP recommends that composite apps use asynchronous communication, especially for write operations, in order to potentially be remote, that is, not running in the same data center as the SAP Business Suite. Why is this so? In a loosely coupled environment, we never know how many systems are involved, whether the systems are available, or how long it takes to complete certain change operations in the backend systems. In addition, all kinds of errors can occur, which must be handled appropriately. It is (almost) impossible to handle business-critical change operations in such an environment synchronously. Developers must not only consider the best case, in which everything works perfectly, but must explicitly consider all kinds of error situations (technical and business errors) and how to respond to them. This goes well beyond simple request-response web service calls and it has severe implications for the composite application’s architecture. Especially if the services you want to call
