On 13.06.2011, at 22:48, Bill Shannon wrote:
> We discussed this "staging" concept quite a bit internally for EE 6.
> In the end we left it out of the platform because it didn't seem to
> solve any problem that couldn't already be solved using other existing
> mechanisms, at least as it was being proposed at the time.
>
> We found *very* few cases where the behavior of existing APIs would
> change based on what "stage" you were in. About the best we came up
> with was that some web application errors might want to produce more
> useful output when in development stage. But since we specify very
> little about what such output should contain, products already have
> the flexibility to vary their behavior in this regard.
>
> If the behavior of the platform APIs don't change based on the stage,
> what is it used for? Well, applications could change their behavior
> based on the stage, but they can already do that using an appropriate
> JNDI environment variable of their own choosing; we didn't really need
> to specify that.
But then you will have to change the application code. With stage dependent application server settings you
would modify the application server settings, without touching the application.
>
> One idea we did consider was to have different resource settings based
> on the stage. You might bind to one database for testing and another
> for production, for instance. Since it's already possible for the
> deployer to do these different mappings at deployment time, this seemed
> like it would only really be useful if you could specify more details
> about the resource you were mapping to, as you can with DataSourceDefinition.
I actually never saw a dedicated deployer role in my projects. There is the "operation" role, but they usually
do not care about the application internals.
What is the experience of the other consultants (Antonio, Reza and Co:-))?
>
> Allowing different resource configurations for different stages
> required more changes to the deployment descriptors than we were
> willing to consider for EE 6. Since we knew that we wanted to consider
> major changes to deployment descriptors in the future, this was another
> reason to defer defining anything about stages for EE 6.
Or we could standardize the Resource settings (e.g. connection pools) on the application server side and make them stage dependent.
>
> So, this may be something we want to consider for EE 7, along with other
> improvements to resource configuration that may be required to better
> support cloud deployment.