Thanks for the pointer, I'll have a look at it.

I once implemented a custom version of RMI that included a 2PC protocol
(which a transaction coordinator and all). The wire protocol was just a
one-way, peer-to-peer message sending system. Messages were serialized Java
objects. I did all this in order to better understand CORBA, RMI and
distributed transactions.

I based all the transactional parts on my reading of two books, one being a
french book, the other being "Concurrent Programming in Java, 2nd Edition"
from Doug Lea (Addison Wesley), chapter 3.6. From those books I learned that
transactions and 2PC are not voodoo. In fact the methods and requirements to
build a transactional system are not complicated (though they can be
expensive to put in practice).

Anyway, the conclusion is that you can implement a distributed transaction
system with 2PC on a one-way, peer-to-peer messaging protocol.

The current web services infrastructure is of course not ready for this, but
it'll have to tackle with the problem and solve it.

Regards,
Nicolas

-----Message d'origine-----
De: David Orchard
A: 'xml-dev'
Date: 22/08/01 22:45
Objet: RE: "Uh, what do I need this for" (was RE: XML.COM:  How I Learne
d t o Love daBomb)

<mondo snip/> 

You presume that transactions between web services is a good and
possible 
thing.  Most people think of 2 phase commit when they think
transactions, 
and I have serious doubts about that.  Satish Thatte wrote a good
position 
paper referencing this, http://www.w3.org/2001/03/WSWS-popa/paper39.
One 
summary would be that 2PC doesn't for web services.

If you mean long-running or compensating transactions, then I agree that

transaction support will be required.

Cheers,
Dave

> 
>  Note that we have a bigger problem which is the non-support of 
transactions
>  by the current web services protocols. We use a kind of architectural
>  workaround for now (based on the fact that we "only" implement an
>  aggregation and presentation layers), but there is no doubt
transaction
>  support will be required one day.
> 
>  That's the reason why I am kind of skeptical about a transactional B2B

use
>  of web services with the current technologies. But as a distributed
>  transaction relies basically on the propagation of the couple 
{transaction
>  monitor ID,unique transaction ID} accross processes, I don't think
this 
is
>  something that can't be done with SOAP.
> 
>  Regards,
>  Nicolas
> 
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