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Object Management Architecture™
The Object Management Architecture (OMA™) embodies the OMG's
vision for the
component software environment. The architecture provides guidance
on how standardization of component interfaces penetrate up -
although not into - applications in order to create a plug-and-play
component software environment based on object technology.
Within
the last several years, the OMG's work in modeling standards
and the proliferation
of middleware technologies dictated an evolution of the OMA. An expanded
vision of the OMA can be found within the OMG's Model
Driven Architecture® (MDA®). The arrival of the MDA does not lessen the
OMA's importance in OMG activity, however, as the OMG continues to require
the guidance of the OMA in its advancement of the CORBA® and related
services specifications (see below.)
The OMA Reference Model
shown above identifies and characterizes the
components, interfaces, and protocols that compose the OMA. Central to
the model - its communications heart - is the Object
Request Broker (ORB) component that enables clients and objects
to communicate in a distributed environment. The
ORB provides an
infrastructure allowing objects to communicate independent of the
specific platforms and techniques used to implement the addressed
objects. The ORB guarantees portability and interoperability of objects over a network of heterogeneous
systems. Specifications
for the xe
"Reference Model" ORB
are contained in CORBA:
Common Object Request Broker Architecture and Specification.
It is worth noting that over its life CORBA has been enhanced to
support embedded and real-time systems as well as those requiring
fault tolerance and other Quality of Service requirements.
The CORBA Services component xe
"Object Services;Object management architecture:Object Services" standardizes the life cycle
management of
objects. Functions are
provided to create objects, to control access to
objects, to keep track of relocated objects and to consistently
maintain the relationship between groups of objects. The
CORBA Services components provide the generic
environment
in which single objects can perform their tasks.
Standardization of CORBA Services leads to consistency over
different applications and improved productivity for the developer. Specifications for the
CORBA Services that have been adopted
as standards by the OMG are contained in CORBAservices:
Common Object Services Specification.
Vertical CORBA Facilities represent components providing computing
solutions for business problems within a specific vertical market (e.g.,
healthcare, manufacturing, finance). Lists of published
and recently
adopted Vertical CORBA Facility specifications are provided on the OMG
web site. Horizontal CORBA Facilities represent those components providing
support across an enterprise and across businesses. A Digital Asset
Management component serves as an example of such a component.
The
Application Objects part xe "Object management
architecture:Application Object;Application Object" of the architecture represents those application objects performing
specific tasks for users. Whether not
standardized or standardized (which typically
represent domain frameworks) by the OMG, these interfaces provide access to
application objects that can invoke
methods on remote objects either statically or dynamically in a
distributed environment through the ORB. An application
is typically built from a large number of basic object classes. New
classes of application objects can be built by modification of
existing classes through generalization or specialization of existing
classes (inheritance) as provided by CORBA Services. The multi-object class approach to application development
leads to improved productivity for the developer and to options for
end users to combine and configure their applications. |
