It can also maintain an implied, apparent, unidirectional, or bidirectional relationship with
its corresponding services. (These relationships are further discussed in the following sections.)
The permission to access a particular service must be granted in a binding contract that can
be monitored and enforced during run-time. A consumer should also commit to service consumption
limits and service availability restrictions. Consumption is typically measured by volume of
exchanged messages and information frequency as agreed on in the contract. Availability, on the
other hand, defines restrictions on access time imposed on a consumer.
SERVICE ROLE. A service is an entity that commits to its offerings through a binding contract
to its subscribed consumers. This stipulated agreement typically outlines a service??™s guaranteed
offerings, availability, consumption rates, and response time. Moreover, services are allowed to
maintain implied, apparent, unidirectional, and bidirectional relationships with corresponding
consumers and peer services.
As previously mentioned in the Consumer Role section, a service also can act as a consumer.
Imagine a service that is not only required to serve its consumer community but is also
obliged to exchange messages with peer services to leverage their offerings.
INTERMEDIARY ROLE. Any service-oriented software asset that is located between the consuming
and the offering providing parties is regarded as an intermediary.
Pages:
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415