??? Increase software isolation. Reduce point-to-point asset associations by employing an
enterprise service bus (ESB). This will introduce a superior asynchronous communication
style between deployed assets and will provide a layer of functionality isolation between
services, consumers, and their enabling middleware and software platforms. Software
isolation can also be achieved by the introduction of brokers or intermediaries that provide
another layer of indirection, further obscuring the identity of the communicating
technological assets.
STATELESS OPERATIONS. To establish a loosely coupled service-oriented technological environment,
a ???stateless operation??? is preferred. In technological terms, this means that the identities
of the various collaborating assets are not necessarily known to their peers. More specifically,
this communication method advocates that a technological asset is both excused from retaining
information about its linked party and exempt from remembering the context of previous message
requests. This rule pertains to all service-oriented technological assets, whether they are services,
legacy systems, or enabling middleware or empowering platforms.
Loose Coupling Perspective 353
Therefore, a loosely coupled service-oriented architecture should encourage the stateless
paradigm over a tightly coupled communication scheme, often called stateful , in which technological
assets are bound by a more restrictive message exchange method.
Pages:
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608