Burke, S (Stephen) wrote:
On the Capacity issue, I think one source of confusion is that the current document shows a single Capacity with three lines linking it to share, MappingPolicy and Environment. That's misleading, because a single instance of Capacity can only ever be linked to one of those. I totally agree. The current StorageCapacity was concieved mainly as a "define once" block for a set of attributes. The current UML implies that an instance of StorageCapacity can be contemporary linked to many different entities.
If we want to keep a common definition for the set of attributes which are in the storageCapacity class, then we could do it. But this should be treated as an abstract class from which other classes inherits the common attributes. I do not see really big advantages for this, therefore your proposal of three different/independent classes could be considered.
For this kind of thing I think it would be better to have three separate Capacity boxes, each linked to only one other object, to make it clear that Capacity is an attribute of some other thing (the Capacity of this Share, etc). In fact the link to MappingPolicy shouldn't be there at all because it's another example of the same kind of thing: a Mapping Policy is an ACL, which has no independent existence, it's also just an attribute of something else (Share in this case). There are other things in the schema which behave like that, e.g. Location (you can only talk about the Location of some other thing).
I understand that this was added to deal with the issue of a "Shared Share", i.e., what is the used size by a certain userDomain if different userDomains can access the same storageShare? how would you address this? - Sergio
(You could say that UniqueID is an extreme example of this - many things have a UniqueID attribute, but by definition they are all different.)
Stephen _______________________________________________ glue-wg mailing list glue-wg@ogf.org http://www.ogf.org/mailman/listinfo/glue-wg
-- Sergio Andreozzi INFN-CNAF, Tel: +39 051 609 2860 Viale Berti Pichat, 6/2 Fax: +39 051 609 2746 40126 Bologna (Italy) Web: http://www.cnaf.infn.it/~andreozzi