Umar Syyid wrote:
>
> Hi Berin,
>
> Berin Loritsch wrote:
> > The compelling example that was given in WSDJ was a very simple web service to
> > find out how much any book from Borders would cost in any currency. The cool
> > part of SOAP and therefore WS is the support for transactions. You can compose
> > larger WS from smaller ones. The example used two existing WS--one from Borders
> > that returns the price of a book (specified by ISBN number) in US currency, and
> > one that converts from one currency to another with the current exchange rates.
> > The web service that was written took markup that specified the ISBN number and
> > the resultant currency type you wanted. The web service would create a transaction
> > that spanned the two other WS calls. First it accessed Border's WS and got the
> > US price. Then it accessed the exchange rate WS to find the price according to
> > the desired currency.
>
> When you say transaction here, are you using the term in the technical
> sense?
Yes. The transactions are part of the SOAP protocol along with security
constraints. Please check the SOAP docs for more info.
> How does the transactional context propagate across varying resource
> types? For example, if one web service is executing an EJB
> implementation how do web services help the transaction to cross
> boundaries to COM+ objects running under MTS? Are web services a better
> integration technology then what exists today? Has someone built
> products that address cross app server interoperability concerns such as
> the one I mentioned above? Or are web services meant to be used only as
> a simple data exchange mechanism?
The transaction mechanism is in the protocol. The underlying implementations
do not change the mechanisms in the protocol. This means that you can have a
web service that uses EJB, that uses a web service using DCOM, that uses a
service using CORBA. The SOAP protocol is able to specify when a request
failed and the calling service then can "rollback" all the changes it made.
Basically SOAP has become your Transaction Authority.
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
