Paul Millar <paul.millar@desy.de> said:
It's preferred in the sense of being a default, use that path if you don't have a reason to do something else.
I don't really buy that as an argument.
It's a statement more than an argument, it's been done like that since the early EDG days and was embedded in the GLUE schema since the storage part was added in 2003, so you're about 15 years late to disagree. You were also involved in the GLUE 2 definition and had a chance to make your arguments then.
A (made up) example: the ATLAS Higgs group should default to /data/atlas/higgs and the ATLAS SUSY group should default to /data/atlas/susy, even though writing into either path would consume resources from the same StorageShare (and writing into /data/atlas would consume resources on a different StorageShare).
ATLAS is really irrelevant here, they have a very elaborate system that imposes a particular behaviour. As far as I remember their reason for wanting multiple paths was to do with files already written so you could tell which storage area an existing path belonged to, but I don't think they have any interest at all in the info system any more. The real use case here is for small VOs who don't have any particular relationship with the sites and are just using opportunistic storage and want to know where their files should go. In that case you need a simple rule that can be implemented mechanically. Anyway, really I find this discussion pointless. The current revision of GLUE 2 is supposed to be backward-compatible, your suggestion is not backward-compatible and therefore should not be accepted. I don't propose to discuss this further. Stephen