Windows NT at the
High End with COM+ from Executive Software Team Jump Executive Software>@@@
It's been roughly 2 years since Microsoft announced and released
COM
(Component Object Model) as part of Windows NT. COM was the beginning
of a long-term plan for true distributed computing, in which any
COM-compliant object, written in any language, could be accessed and
utilized by any other COM-compliant object, no matter the native
language or platform. (The entire subject of distributed computing was
discussed at length in eLetter Volume 1 Issue 5, and Volume 2 Issues 1
and 2, available at the eLetter archive web site - http://www.execsoft.com/eletter).
With COM+, Microsoft is taking COM up one major level to that of a
complete application server. Application servers, which are
traditionally hardware-and-software combinations provided by third party
(other than Microsoft) companies, are the middle tier in a distributed
computing model. The upper tier would be the server, containing
databases and other server-supplied data, and the lower tier would of
course be the client which contains user-specific applications or
portions of applications and the data the user is immediately using.
COM+ achieves this next level by greatly extending existing COM
services, by adding new additions such as dynamic load balancing and
interaction with Microsoft Transaction Server (MTS).
Microsoft Transaction Server, introduced in 1996, was the first
commercially available software to combine individual distributable
components with transactions, making transaction-based distributed
computing a much more ready-made possibility. MTS introduced a number
of innovations, such as automatic transactions, which allow configuring
a component's transactional requirements when that component is
deployed; automatic thread support, which allows application developers
to write single-threaded components and allows MTS to assign threads to
those components as needed; process isolation through packages, in which
individual applications can be grouped into one or more packages and
each package can run its own process; and configurable security.
COM+ was announced almost a year ago at the 1997 Professional Developers
Conference, and has now been released in Preview form on the Windows NT
5.0 Beta 2 CD. Microsoft is expected to announce shortly that COM+ will
be shipped as part of the operating system in the final release of
Windows NT 5.0.
The overall goal of Microsoft's Distributed Computing model is to be
able to have a fully scaleable environment in which distributed
applications can be quickly and easily developed, and can be implemented
with a minimum of effort. The applications and data can be quickly
accessed and used by end-users with no thought to their location (local,
network, or Internet-accessed) and no attention from system
administrators on tasks such as load-balancing; in the ideal environment
the operating system will take care of balancing workload and traffic
flow.
Being the important release that it is, COM+ will no doubt receive
prominent attention as the Windows NT 5.0 release draws near. We'll
keep you posted as more information becomes available. To find out what
Microsoft is currently saying about it go to: