[jboss-as7-dev] RFC: write-attribute*s* / update-resource operation

[Brian Stansberry]

On 4/7/11 8:04 AM, Heiko W.Rupp wrote:
> Hi,
>
> sometimes it is required to change multiple attributes of a node at once.
>
> Currently this needs to be done via composite operation that contains
> multiple write-attribute calls.
>
> If would be nice if there would be an operation that allows to
> update multiple attributes (sub elements?) of a resource at once.
>

I see two situations here:

1) Each individual write-attribute can be applied to the runtime service 
in a separate step, with the service state not being incorrect in the 
middle (i.e. after step 1 is applied but step2 hasn't been applied.) 
Grouping them in a composite op ensures they'll all succeed or all roll 
back.

For this situation, a composite op already handles it. I can see the 
desire for a less verbose variant for the case where all the steps are 
"write-attribute" on the same resource, but gosh, we've got a lot of 
critical stuff to do. Feel free to open a JIRA (unless what's wanted at 
[1] is actually this), but I can't promise anyone will get to it. :(

2) The individual changes all need to be applied to the runtime service 
at once. In this case the individual attributes shouldn't be writable 
via write-attribute at all; the resource should expose a separate 
operation that takes multiple parameters.

For this situation, a generic "update-resource" operation where every 
attribute that needs changing is a param would be convenient, but I'm 
extremely doubtful that it could be properly implemented. Every 
subsystem would have to write a custom handler for each resource that 
could properly deal with all permutations of incoming params.

[1] https://issues.jboss.org/browse/JBAS-9161

-- 
Brian Stansberry
Principal Software Engineer
JBoss by Red Hat