Does ws-bpel support local operations which are not released to web service?

[Van Caesar <fa...@gmail.com>]

Here a conceptual problem about ws-bpel troubles me. In my thought, as a
language, bpel is based on web service, so it can describe process with the
partnerlink's operations released to web service. We all know, web service
need more system resource, therefor, most time we need to use local
operations which are not released to web service, such as the classes stayed
in internal memory.

Bpel is an advanced computer languge, what I want to know is that whether it
complete some lower functions or not. Now, we want to use apathe ode to make
business process come true.


-- 
Van Caesar

Re: Does ws-bpel support local operations which are not released to web service?

[Alex Boisvert <bo...@intalio.com>]

Hi Van,

While keeping in mind that BPEL was designed to solve the "programming in
the large" problem, there are multiple approaches to carrying "cheap"
compute operations in BPEL:

1) Using XPath function extensions
    (Note that your functions should ideally not have any side-effects.)

2) Using an integration layer that supports in-VM code invocation
    Both JBI and Axis2 integration layers allow you to do this (although
both require in-memory XML representation)

3) Extending the language with custom activities  (e.g., BPEL4J)

4) Extending the language with custom expression language
    (We already support XPath 1.0/2.0 and call-outs to XSLT 1.0/2.0)

So far, my experience is that using #1 and #2 is best for most
environments.   If you're thinking about #3 and #4, it's often worth
revisiting your SOA architecture first and making sure you are correctly
following the design principles (e.g., coarse-grained services,
loose-coupling, etc.).   The benefits of extending the language need to be
judiciously weighted against the loss of portability of your processes as
well as creating and sustaining a toolset that supports language extensions.

regards,
alex


On 7/19/07, Van Caesar <fa...@gmail.com> wrote:
>
> Here a conceptual problem about ws-bpel troubles me. In my thought, as a
> language, bpel is based on web service, so it can describe process with
> the
> partnerlink's operations released to web service. We all know, web service
> need more system resource, therefor, most time we need to use local
> operations which are not released to web service, such as the classes
> stayed
> in internal memory.
>
> Bpel is an advanced computer languge, what I want to know is that whether
> it
> complete some lower functions or not. Now, we want to use apathe ode to
> make
> business process come true.
>
>
> --
> Van Caesar
>