Re: What are web services ?

Although no single, authoritative definition exists for basic terms like "service" and "Web Service", here are some fundamental characteristics that some folks believe that anything described as a "Web Service" should possess:

(1) Can interact with it through the WWW;
  

(2) Platform- and programming language-agnostic;
(3) Interface & invocation requirements are well-described;
  

(4) XML-encoded interaction mechanism;
  

(5) Payload most often is XML;
  

(6) Loose coupling between invoker and Web Service;
  

(7) Performs a specific, well-defined function;
  

(8) May invoke other Web Services;
  

(9) Standards-based;
(10) Has the ability to perform its functionality synchronously or asynchronously, as needed; (i.e. does not use synchronous interaction when asynchronous is best, and vice-versa);
  

-- 
Regards,
Razvan

SCJP preparation material:

http://www.mihaiu.name/2004/sun_java_scjp_310_035/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test1/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test2/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test3/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test4/index.html

Joe

Joseph Chiusano
Booz Allen Hamilton
Visit us online@ http://www.boozallen.com

  

-----Original Message-----
From: Paul Downey [mailto:paul.downey@w...] 
Sent: Tuesday, May 31, 2005 2:26 AM
To: Rex Brooks
Cc: xml-dev@l...; Michael Kay; 'Razvan MIHAIU'
Subject: Re:  What are web services ?

Rex,

I actually think Michael's answer was bang on target. You 
only have to look at the archives of the W3C Web Services 
Architecture Working Group to see the difficulties involved 
when trying to gain consensus on the definition for basic 
terms like "Service".

    

since it is almost guaranteed that the future of computing will be 
dominated by the paradigms being developed in this field.
      

How far into the future are we talking, here?
The whole of computing, guaranteed, really?

Web services do have some significant vendor backing, but 
still have some real political and technical issues and so 
much to prove. The potential to reach the 'Web'
vision for services remains, but is likely to be somewhat 
different to the tower of Babel currently being battled for.

As someone wise said recently (i wish i could remember who):
the future is often out there in the long grass, where no-one 
is watching.

Paul



    

While this is true for the perpetual world of con artists and 
grifters, and those on whom they prey, and for the equally 
      

perpetual 
    

professional gadflies whose avocation appears to be to puncture the 
also perpetual puffed up human egotists who appear to be born 
"experts" on just about everything and whose love of their 
      

own voices 
    

vocally or verbally seems to know no bounds.

However, there is a growing body of standards and practices 
      

for both 
    

loosely coupled but well-bound WSDL and SOAP based web services AND 
RESTful web services based largely on structural 
      

capabilities inherent 
    

in the current and future Web Services Architecture 
      

promulgated by the 
    

W3C.

Please be aware when you toss out the makings for new 
      

assaults in this 
    

permathread that asking for or providing short answers for how to 
build, publish service descriptions, establish reliable connections 
for web service consumers and transact reliable, secure web service 
operations to deliver valuable, cost-worthy functionalities 
      

over the 
    

web is not wise and most likely to produce poor definitions 
      

and wider 
    

misinformation than we already have.

Since I have been working for three and half years in the 
      

OASIS WSRP 
    

TC and for the last few months in the newly formed SOA 
      

Reference Model 
    

TC, I can vouch for how difficult it is to develop sound, reliable 
specifications, definitions and practices for this arena, 
      

especially 
    

since it is almost guaranteed that the future of computing will be 
dominated by the paradigms being developed in this field.

Like it or lump it, you will be dealing with it, so spit 
      

into the wind 
    

at your own risk. However, it is always tremendous fun to 
      

watch while 
    

pedants and gurus expound on these topics.

My own position is to attempt to help shape this new 
      

technology into 
    

more workable pathways and learn it from the inside out while it is 
possible to do so. Three years ago it was almost pure hype 
      

with a tiny 
    

proportion of real work and a few major vendors vying to "own" this 
space. Now it is due to become, in the  world of  public 
      

perception, 
    

the province of equally perpetual gurus who have an almost 
irresistible compulsion to evangelize in these early stages of 
development and who tend to become "bleeding deacons" decrying the 
loss of true vision and purpose as what they consider their 
brainchildren develop their own lifecycles apart from the 
predilections of early adopters and true believers alike.

This opinion is based on observing similar processes over 
      

the course 
    

of the last 30 years of tech development..

Ciao,
Rex

At 10:29 AM +0100 5/30/05, Michael Kay wrote:
      

OK, here's my answer. The term "web service" means anything the 
speaker wants it to mean. Like "service oriented architecture" or 
"native XML database" or "electronic business" it's a 
        

fuzzy term that 
    

different people will define in different ways, depending on what 
they are trying to sell you.Michael Kayhttp://www.saxonica.com/
        

From: Razvan MIHAIU [mailto:mihaiu@m...]
Sent: 29 May 2005 17:43
To: xml-dev@l...
Subject: Re:  What are web services ?

     This is not that much off-topic. Please make the courage to 
answer :-(
          

Hi,


             Were can I find a good definition of this ? A web 
service must be based on SOAP in order to belong in this 
            

category ?
    

A web service must use XML for transferring data (like 
            

SOAP) ? Can 
    

we have web services without WSDL and UDDI ?


 Regards,
 Razvan
--
 Regards,
 Razvan

 SCJP preparation material:

http://www..mihaiu.name/2004/sun_java_scjp_310_035/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test1/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test2/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test3/
index.htmlwww.mihaiu.name/2004/sun_java_scjp_310_035_test4/
index.html
  
            

--
 Regards,
 Razvan

 SCJP preparation material:

http://www..mihaiu.name/2004/sun_java_scjp_310_035/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test1/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test2/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test3/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test4/index.html
          

--


Rex Brooks
 President, CEO
 Starbourne Communications Design
 GeoAddress: 1361-A Addison
 Berkeley, CA 94702
 Tel: 510-849-2309

      

--
http://blog.whatfettle.com


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-- 
Regards,
Razvan

SCJP preparation material:

http://www.mihaiu.name/2004/sun_java_scjp_310_035/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test1/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test2/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test3/index.html
http://www.mihaiu.name/2004/sun_java_scjp_310_035_test4/index.html