[glue-wg] Datastore proposal

[Burke, S (Stephen)]

glue-wg-bounces at ogf.org 
> [mailto:glue-wg-bounces at ogf.org] On Behalf Of Burke, S (Stephen) said:
>   This would be linked to the existing StorageResource object with a
> one-to-many relation, i.e. one Resource could manage many Datastores
> (Castor manages tape and disk) but not vice versa, one Datastore can
> only be managed by one Resource - if there are e.g. multiple sets of
> disk servers managed by several different software systems that would
> constitute multiple Datastores.

One more thing while I think of it before I give up for the night ... I
realised that at RAL we already have something more complicated than
this. There is a separate castor instance for each of atlas, cms and
lhcb, plus one for everyone else. Those instances have separate disk
pools, hence they are separate Resources with separate Datastores.
However, there is only one tape system shared between all of them, which
would imply one Resource and one Datastore. I think the root of the
problem is that the Resource can in fact be a hierarchy, Castor manages
disk directly but the tape part goes through another layer of software.
Whether or how we want to represent that I'm not sure ... probably just
have a separate tape Datastore per instance regardless?

> relation between
> the Share and whichever DataStore(s) store the data for that 
> Share. That
> can be one to many, e.g. if Custodial/Online uses disk+tape, 
> as in WLCG.

Of course I meant many to many, obviously one Datastore contains many
Shares.

Stephen