An enterprise service bus (ESB) is centralized integration middleware: it transports messages while applying validation, authorization, encryption, dynamic routing, and auditing. section 7.1.1
This reverses the smart endpoints and dumb pipes pattern. Instead of leaving processing at service endpoints, the ESB concentrates integration logic in middleware, which can become a development bottleneck and a logical single point of failure. section 7.1.1
The architectural trade-off is:
- Centralization standardizes cross-cutting concerns such as encryption and auditing, but couples services to a monolithic integration component. section 7.1.1
- A service mesh separates business logic from integration responsibilities and makes those responsibilities configurable through infrastructure components. section 7.1.1
Figure 7.2 Integration logic is handled by smart middleware (the enterprise service bus).
Use the architecture figure to compare smart middleware with endpoint-owned processing. section 7.1.1
