Cloud Computing and SOA Convergence in Your Enterprise: A Step ...

Integration-as-a-Service 55
The advantage of platform-as-a-service is that you can access a complete
enterprise-class development environment at a low cost and build complete
enterprise applications, from the data to the user interface. The disadvantage
is that many of the platform-as-a-service vendors leverage proprietary programming
languages and interfaces; thus, once your application is there, it
may be difficult to move it to an on-premise server or another platform-as-aservice
provider.
Integration-as-a-Service
Integration-as-a-service is the ability to deliver a complete integration stack
from the cloud, including interfacing with applications, semantic mediation,
flow control, and integration design. In essence, integration-as-a-service includes
most of the features and functions found within traditional EAI (enterprise
application integration) technology but delivered as a service.
Integration is a tough problem to solve, and integration on demand does
not make that any easier. The core notion is that you link up to many information
systems, either at the data or behavior level, and abstract information
and/or behavior from those systems to be delivered with one or many systems,
either within the same enterprise or within companies.
There are many books on integration, so we do not get into it too much
here. However, any integration engine, on-premise or in the cloud, has to support
some basic functions, including (to name just a few):
Transformation
Routing
Interface
Logging
Transformation means that you can convert the information semantics
from one system to the information semantics of another system, so the target
system can receive information in a format it understands.
Routing means that information is routed to the correct systems on the
basis of predefined logic (called intelligent routing).
Interface means that you can connect into the source or target systems
using whatever interface they expose.
Logging means that you can log all integration activities, such as messages
flowing in and out, as well as other events.