A question from the Tuscany SCA Chinese ForumI: Is SCA container always required to deploy SCA composite applications?

[Raymond Feng <en...@gmail.com>]

Hi,

A user raised an interesting question in the Tuscany SCA Chinese Forum [1]. 
I think it would be useful to share it in English on this mailing list.

The question is:

To deploy an SCA assembly in a distributed environment, is a SCA container 
(such as Tuscany) required for each of the runtime that hosts and runs part 
of the composite application?

The user thinks it would be very invasive if the answer is "yes". You can 
see the not-so-good google translation of the original thread at [2].

What do you think?

Thanks,
Raymond

[1] 
http://groups.google.com/group/tuscany-sca-chinese/browse_frm/thread/a0d2afb2587ab364
[2] 
http://translate.google.com/translate?u=http:%2F%2Fgroups.google.com%2Fgroup%2Ftuscany-sca-chinese&hl=en&ie=UTF8&sl=zh-CN&tl=en 

Re: A question from the Tuscany SCA Chinese ForumI: Is SCA container always required to deploy SCA composite applications?

[Simon Laws <si...@googlemail.com>]

On Tue, Oct 28, 2008 at 6:56 PM, Raymond Feng <en...@gmail.com> wrote:

> Hi,
>
> A user raised an interesting question in the Tuscany SCA Chinese Forum [1].
> I think it would be useful to share it in English on this mailing list.
>
> The question is:
>
> To deploy an SCA assembly in a distributed environment, is a SCA container
> (such as Tuscany) required for each of the runtime that hosts and runs part
> of the composite application?
>
> The user thinks it would be very invasive if the answer is "yes". You can
> see the not-so-good google translation of the original thread at [2].
>
> What do you think?
>
> Thanks,
> Raymond
>
> [1]
> http://groups.google.com/group/tuscany-sca-chinese/browse_frm/thread/a0d2afb2587ab364
> [2]
> http://translate.google.com/translate?u=http:%2F%2Fgroups.google.com%2Fgroup%2Ftuscany-sca-chinese&hl=en&ie=UTF8&sl=zh-CN&tl=en
>

I think it depends on how you view the relationship between the SCA assembly
model and runtimes that host parts of the distributed composite application.
Three different views come to mind;

1. An SCA runtime interprets the SCA assembly model and takes direct
responsibility for running component services, e.g. the Tuscany SCA runtime
creating instances of components implemented in Java
2. An SCA runtime interprets the SCA assembly model but configures another
runtime to start component services, e.g. some SCA runtime interacts with an
EJB container to start up JEE modules with the correct configuration
3. The SCA assembly model simply describes component services that are
already running and has no impact on their configuration, e.g. we used to do
this with the catalog-ejb module in the store tutorial.

In Tuscany today we only do 1 althought we did do a bit of 3. I imagine 2
may come into play when we get further with the JEE integration.

Simon