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Nov 8, 2013 (3 years and 7 months ago)

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Web Services?

(
Times of India,
Feb 11
,

200
2
)


In the last three columns I wrote about XML, SOAP & UDDI. XML, SOAP & UDDI together (like
the trio


Brahma, Vishnu, Mahesh) enable a whole set of services to be offered over the Net in the
name of Web Services
. The arrival of Web Services also represents a new paradigm of software being
delivered as a service that is likely to fundamentally change the very production of software services.
Let me explain.



Computing for long has been built around a “computer”;
though Sun Microsystems as a visionary
company envisioned “Network is the computer” way back in 1984, the idea could not be translated
into practice all along. We have come a long way from computing restricted to a mainframe
computer to which few had acces
s; there is a computer on every desk practically today (the vision of
Microsoft Chief Bill Gates); networking is a reality today and distributed computing has matured.
Programming language Java with its philosophy of “write once; deploy many time” has take
n cross
-
platform development to new heights. The philosophy of object oriented programming as a concept
and object oriented languages like c++ / Java / c# have given a practical way to put “re
-
usability”
into practice. RPC (Remote Procedure Call) as an abs
traction, the idea of applets, servlets, “plug
-
in”
and a host of scripting languages and the broader notion of client
-
server computing, n
-
tier
architecture, middleware etc., have taken us closer to network computing considerably. Yet, we are
not in a posit
ion to completely offer computing over the Net today; object philosophy predates
ubiquitous network availability; Java and the resultant JVM (Java Virtual Machine) allowed
heterogeneity of computing at the base level but yet assume homogeneity at “run time
”. IIOP from
OMG and RMI from Java camp take RPC to a greater height, but still falls short of true network
computing.



XML
-
based message passing through SOAP is a powerful notion that can take distributed computing
to network and beyond “computer”. Since

XML is text and XML parsers can decode the structure of
the data that is “encapsulated” in XML, almost “on the fly”, XML & SOAP together permit
computing over the Net. Of course we need UDDI so that the participants in this process


a set of
computers an
d the processes that run on them


can automatically publish the services that they can
offer, discover the services that are available and deliver the services over the Net


completely
automated (through program
-
to
-
program communications).


Let me give a
n example. A typical application of you buying a book / music online today requires
that the book store / music store (like FabMart) publish their catalogue online on their site, register
with several search engines and make arrangements with payment gatew
ay (like BillJunction), provide
for presentation program on their site etc., For you the user to buy, you have to visit the site, become
a member, do an online transaction, provide all the information, order the book, and provide
authorization for payment.

If you need to do comparative shopping, you need to visit every site, do a
manual comparison and decide on the purchases. Imagine a situation where you need to “automate”
this process


may be for your Library, Association or a Club. Your automation progr
am can be
“fragile”


if the service providers change their sites, site layout, payment gateway providers etc., your
automation programs will NOT work. Imagine dealing with multiple stores, the nightmare will be
obvious. With XML, SOAP & UDDI (all W3C stan
dards) and Web Services framework your
automation program will be “rugged”. The service providers like FabMart can change their sites (host
in a different place, re
-
design layout, offer alternate supplies, payment gateways), you can change
your bank, credi
t card etc., and yet the SAME programs will work. Through UDDI you can discover
new sources (competitors to FabMart) that have entered the market and use “intelligent agents” to
do comparative shopping


in an automated manner.



The example is just the ti
p of the iceberg. With imagination and creativity you can dream up million
possibilities. A whole range of standardized services, like authentication service (the controversial
Microsoft Passport service) would be routinely available that many of the appli
cations that you build
today would get “unbundled” to take advantage of these standardized services. In a sense, significant
number of applications would be re
-
packaged as a set of system engineered / assembled services
(authentication, information collect
ion, database query, database update, automated message / mail /
notification delivery, report writing, formatting etc.,). In that sense software construction would
undergo a paradigm shift


from “building” to “assembly”. That is the promise of Web servic
es


watch out for this excitement to unfold over the years.



For pointers for your study I would strongly recommend the following sites



1.

The HBR article on “Your next IT strategy” (Harvard Business Review October 2001) is an
excellent place to get the “
big picture”


2.

Gartner Magic Quadrant on Web Services (September 14, 2001) gives in Gartner style, the
business side of Web Services and the role of different vendors in this game.


3.


GiGa Report “Web Services: Emerging as a Broad Internet Application Integr
ation
Standard, Bigger Than Just Microsoft.NET” (June 6, 2001)


is an “Analyst View” of Web
Services


4.

My own articles that appeared in Economic Times (December 20, 2001) providing a
managerial perspective and the one that appeared in CIO India Magazine (N
ovember 2001)
takes a CIO perspective on Web services will provide alternate views on Web services.


5.

A great site for tutorial, examples, code, quiz and training (all free), and my favourite is
W3Schools site (
www.w
3schools.com
)

6.

The tutorials on devxpert site (
http://www.devxpert.com/tutors/
) are great for first
-
time
users


7.

The SAMS Publication “Building Web Services with Java


Making Sense of XML, SOAP,
XDSL & UDDI”

by Steve Graham and six others is the only book that is widely available
today (January 2002). Many are in the pipeline.


8.

“ The Simplest Way to Define .NET”
-

Sanjay Parthasarathy, Vice President of Platform
Strategy, Microsoft Corporation

December 21, 20
00


gives insight into Microsoft version of Web Services


9.

Web Services, an Interview with Robert Hess March 19, 2001 (Microsoft Site) provides far
more clarity on this emerging idea


(The author is the Director of the Indian Institute of Information Techn
ology, Bangalore (IIIT
-
B).These are his personal reflections on the IT industry, more so from an Indian perspective.The
inputs are from journals, magazines, sites, newsletters and newspapers. He can be reached at :
ss@i
iitb.ac.in

)