users@javaee-spec.java.net

[javaee-spec users] Re: [jsr342-experts] Re: Staging (was Re: Configuration)

From: Pete Muir <pmuir_at_bleepbleep.org.uk>
Date: Mon, 13 Jun 2011 22:57:38 +0100

I think with multiple "views" onto the app that we will see with multi-tennancy that this can become more interesting.

On 13 Jun 2011, at 21:48, 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.
>
> 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.
>
> 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.
>
> 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.