[jboss-as7-dev] Recent profile changes

[Brian Stansberry]

On 7/1/11 5:06 AM, Kabir Khan wrote:
>
> On 29 Jun 2011, at 17:46, Brian Stansberry wrote:
>

>>>>
>>>> One not totally satisfying way to clarify things is to have a notion of
>>>> an "abstract" profile. An abstract profile cannot be applied to a server
>>>> group. A change to an abstract profile applies to all profiles that
>>>> include it and don't themselves override the relevant subsystem. Other
>>>> profiles could only include abstract profiles.
>>>>
>>
>> WDYT about this 'abstract' notion? Whether or not we require a 'copy'
>> operation to decouple the included subsystem, I don't like having a
>> profile be both inherited and directly applied to servers. It makes it
>> too difficult to determine the user's intent when they modify the profile.
>
> I don't really see the difference between an an abstract profile or any other included profile. So we have "abstract-profile" which can't be used in a server group, instead you would need to create a "concrete-profile" which includes "abstract-profile" and then use "concrete-profile" in the server group. So if "concrete-profile" is empty apart from the include I don't really see the benefit?
>
>

Scenario: you have profiles A and B, with B including A. You have server 
groups A and B with group A using profile A and group B using profile B.

Now you want to increase some thread pool size on the servers in group 
A. But not the servers in group B. This can't be done without creating a 
new profile C and shifting the A servers over to it.

An abstract profile only offers a benefit if we allowed a profile that 
inherits another profile to override subsystems.

It's not a huge benefit though; probably not worth it. The junior admin 
at 3AM could still easily go into profile A intending to only affect the 
servers in group A and unknowingly update the group B servers as well. 
The odds of his doing that might be slightly reduced, since there would 
be no servers running profile A directly so he might be more inclined to 
understand the implications of his change.


-- 
Brian Stansberry
Principal Software Engineer
JBoss by Red Hat