One of the key decisions to be made is whether integration should be real-time (synchronous) or asynchronous. The following table analyzes both messaging approaches and describes the scenarios when one should be selected over the other:
|
Type |
Pros |
Cons |
Good for |
Examples |
|
Synchronous |
Fail-safe communication. Error/exception handling. |
Tight coupling between systems. Blocks sender until the receiver is finished. Network dependency; calling system must be available.
|
Transaction processing across multiple systems. |
Mobile app/handheld for PO receiving, SO picking, inventory on-hand, and so on. |
|
Asynchronous |
Decoupled systems. Does not block sender. The integrating system doesn't need to be available. Messages can be queued. |
Reliability. Error/exception handling.
|
Publish and subscribe. Request reply. Conversation. |
General ledger, sales order, purchase orders, and master data integrations. |
In general, asynchronous messaging architectures are preferred and recommended for enterprise integration as it allows for a loosely coupled solution. The asynchronous integration pattern overcomes the limitations of remote communication, such as network latency and the unreliability of the connected systems. The issues of reliability and exception handling in asynchronous messaging can be overcome by utilizing acknowledgments, status checks, and logging features.