Components and the Internet
Businesses can use component-based applications to project a business
presence onto the Web.
The simplicity, ubiquity, and industry momentum of standard Internet
protocols such as the HyperText Transfer Protocol (HTTP) make the Internet
an ideal technology for linking application components that span computer
boundaries. HTTP is easy to program, is inherently cross-platform, and
supports an accessible, universal naming service. And much of the
excitement around the Java language derives from its potential as a tool
to build distributed component applications for the Internet.
www.tartoos.com
DCOM enables these component applications to operate across the Internet.
DCOM is ideally positioned to become a mainstream Internet technology for
business applications:
www.tartoos.com
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Transport-neutral—DCOM enables components to communicate with
each other over any network transport, both connection-oriented and
connectionless, including TCP/IP, UDP/IP, IPX/SPX, AppleTalk, and HTTP.
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Provides distributed Java today—Since DCOM is language neutral,
Java applets can communicate directly with each other over the Internet
(and with any ActiveX component, regardless of authoring language).
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Evolutionary technology—In addition to Java support, DCOM enables
components written in other languages, including C, COBOL, Basic, and
Pascal, to communicate over the Internet, providing a growth path for
existing applications to support Web technology. www.tartoos.com
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Common components for the browser and Web server—Since ActiveX
components can be embedded into browser-based applications, DCOM enables
a rich application infrastructure for distributed Internet applications
using the latest browser technology.
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Security—DCOM integrates Internet certificate-based security with
rich Windows NT-based security, combining the best of both worlds.www.tartoos.com
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Standards-based—Microsoft is working with Internet standards
bodies, including the IETF and the W3C, to offer DCOM to the Internet
community as an open technology. DCOM is based on the Open Group DCE
RPC, an open and widely-deployed communications technology. The DCOM
wire protocol extensions have been submitted as an Internet draft and
are available at
http://www.dc.luth.se/doc/id/draft-brown-dcom-v1-spec-00.txt.
Components and the
Enterprisewww.tartoos.com
As distributed applications built from simple components and Internet
protocols emerge, a new set of enterprise platform services for component
applications will be required.www.tartoos.com
A key goal of any component software architecture is to separate business
logic—how a tax component calculates tax rates—from execution
logic—whether the tax component runs in a browser or on a multiprocessor
server. DCOM extends this separation even further because the same
components can communicate with each other across processes in a single
computer or between computers over the Internet.
However, components by themselves do not solve all of the issues of
enterprise application complexity. For example, suppose a business wants
to rapidly build and deploy a customer order entry application that
involves five different areas of functionality: tax calculation, customer
credit verification, inventory management, warranty update, and order
entry. The application will be built from five separate components and
will operate on a Web server. How does the developer handle exceptions?
System failures? Network outages? Peaks in performance load? Must these be
hand-coded into the application? www.tartoos.com
It defeats the two main goals of component-based development—fast time to
market and lower development costs—if companies are forced to hand-code
the mission-critical services that are required for online production
systems.
To address enterprise requirements for a distributed component
architecture without sacrificing rapid development and cost effectiveness,
Microsoft is integrating DCOM into the Active Server. The Active Server is
a series of technology services that speed deployment of component-based
applications for the Internet and corporate intranets. These services
include:www.tartoos.com
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Transactions—traditional rollback and recovery for
component-based applications in the event of system failure.
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Queuing—integration of component communication with reliable
store-and-forward queues, which enables component applications to
operate on networks that are occasionally unavailable.
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Server scripting—easy integration of component applications on
the server with HTML-based Internet applications.
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Legacy access—integration of component applications with legacy
production systems, including mainframe systems running CICS and IMS.
The Active Server technologies use publicly obtainable Internet protocols
and are currently available.
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