RE: Compositions Types:Static and Dynamic

Daniela,

Thanks very much for your kind attention and reply to my question. And
that's why I said here before that the semantics of WSDL interface is not
the semantics of the Web service. 

One more question is about the relationship between dynamic service
composition and dynamic service invocation. If the purpose of dynamic
service composition is for dynamic service invocation, given the example of
retrieving an aerial photo from Microsoft's Terraservice, how such dynamic
composition will enable the dynamic invocation? In this case, the known WSDL
documents can be identified, thus you know the IOPEs for this task. 

I never tried the dynamic invocation in Java, but in .NET, I know it's a
difficulty to build dynamic invocation in the traditional WSDL approach.
Your kind advice and suggestions to such issues will be greatly appreciated.

Best wishes,

Xuan

-----Original Message-----
From: Daniela CLARO
To: public-sws-ig@w3.org
Sent: 4/18/06 3:53 AM
Subject: RE: Compositions Types:Static and Dynamic


Thank you all for the answers...
Answering your last question Xuan :
"How can you know by reading the WSDL document which other service(s)
would be required, and what are the input/output for the other
service(s)?" 

In my opinion only using WSDL you cannot know what services could be
required, because many web services that do different tasks can have the
same input/output. It is because that I use IOPE to know which service
comes first and which one comes after. And using preconditions I can
know which service is a prerequisite. 

Best regards, 
Daniela  

-----Message d'origine-----
De : Shi, Xuan [mailto:xshi@GEO.WVU.edu] 
Envoyé : vendredi 14 avril 2006 18:25
À : Daniela CLARO; ''public-sws-ig@w3.org ' '
Cc : Shi, Xuan
Objet : RE: Compositions Types:Static and Dynamic
Importance : Haute

By the way, ESRI's address geocoding Web service is just such a typical
and good example for your kind attention since the geocoding service
(s1) depends on the outcome of another service (s2) in order to be
executed.

How can you know by reading the WSDL document which other service(s)
would be required, and what are the input/output for the other
service(s)?

-----Original Message-----
From: Shi, Xuan
To: 'Daniela CLARO '; 'public-sws-ig@w3.org '
Cc: Shi, Xuan
Sent: 4/14/06 12:10 PM
Subject: RE: Compositions Types:Static and Dynamic

A good way for discussion is to use living Web services to demonstrate
the ideas about static or dynamic service composition. Here is a typical
example for reference:

Do you want to get a 1 or 2 meter resolution arieal photo of your home
place? You can get the photo by aggregating the following living Web
services:

1. ESRI's address geocoding Web service that helps you to get the
latitude and longitude of your home address. Service URL is:

http://www.arcwebservices.com/services/v2006/AddressFinder.wsdl

2. Microsoft's TerraService can give you arieal photos or satellite
images with resolution from 1 m to 2000 km. Service URL is:

http://terraservice.net/TerraService2.asmx?WSDL

Using .NET as an example, for static invocation, programmers has to "Add
Web Reference" first to get a service stub, write OOP program based on
the stub and invoke the service.

For dynamic invocation, without adding any Web references, programmers
has to create a new wsdlService class that has a function
InvokeWebService(url, namespace, ......) which returns an object as the
output.

Given the example of AddressFinder Web service, (I am afraid you cannot
figure out how to invoke this service by just reading this WSDL
document, even though you may wish to add semantic annotations into it),
the object returned from invocation is a GeocodeInfo object, which
contains "candidates" that has an array of GeocodeCandidate. Each
GeocodeCandidate has a point class that has x, y coordinates and
information about the coordinate system. 

When you get x, y values through your dynamic composition and invocation
process, then you can use them in TerraService to retrieve the arieal
photos you want.

If anyone can tell us how to use OWL-S, WSMO, WSDL-S or something else
to implement a dynamic composition and invocation to retrieve arieal
photos of your home address from ArcWeb service and TerraService, then
we can see the great achievement in this field. Otherwise, we have to
find some other ways to do this job.

Best wishes,

Xuan

-----Original Message-----
From: Daniela CLARO
To: public-sws-ig@w3.org
Sent: 4/12/06 4:03 AM
Subject: Compositions Types:Static and Dynamic


Hi all,
 I want to hear from you about composition types. Actually, I classified
the composition of sws in two categories: static compositions and
dynamic compositions. 
>From static composition I mean the compositions that know iin advance
all services that will belong to the composition, for example, the use
of workflows, that we decide before which services will participate to
the compostion. Do you have other examples from static compositions? 

About dynamic composition, it is the use of dynamic workflow, the use of
planning to compose, the use of graphs. I mean that we don't know in
advance which services will participate to the composition. Moreover, if
I have a service s1 that need another service s2 in order to be
executed, so the dynamic composition should find this other service s2
and put s2 in the composition. Isn't that? Do you have other examples of
dynamic compositions? 

So I want to hear from you what do you think about this classification
and examples of static and dynamic compositions. 

Thanks in advance,
Daniela CLARO

Received on Tuesday, 18 April 2006 14:41:49 UTC