users@javaee-spec.java.net

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

From: Bill Shannon <bill.shannon_at_oracle.com>
Date: Mon, 13 Jun 2011 16:08:54 -0700

I'm not quite sure how these two concepts tie together. Can you say more
about what you had in mind?

Pete Muir wrote on 06/13/11 02:57 PM:
> 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.
>