Obviously this very generic
definition refers to many mediating roles that are imperative to the implementation of a service
ecosystem (refer to the Intermediary Relationship section for more details).
Without an intermediary intercepting party it would be difficult to enhance service security,
enrich message content, and even improve the dispatching mechanisms of messages. True, these
responsibilities can be assigned to the services and their corresponding consumers themselves.
But the aim here is to offload these enhancement and augmentation tasks from the participating
parties to foster a loose coupling design environment, and create an agile computing landscape.
SERVICE DESIGN VISIBILITY ASPECTS
What does it mean to be visible? Do services maintain relationships only with visible entities?
The visibility aspect depends on a service??™s exposure level to its consumers or peer services.
In other words, a service is visible only when access is granted to its exposed interfaces. But
services can maintain associations5 with their consumers and other services even when they are
not publicly visible to each other.
A service should have the capacity to protect its internal operations, hide its implementation,
and still be able to propagate messages to its contained constituents. True, autonomous
services that are not tightly coupled to their peers and are not contained in aggregated structures
can be exposed publicly to subscribed consumers.
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