[glue-wg] When is data stale?

[Jens Jensen]

On 25/03/2015 17:41, Paul Millar wrote:
> 2. should the agent (BDII) add an Entity.CreationTime if the source
> does not provide one?
No; that would make the value useless because it would not be used
consistently with those that set it.
>
> 3. what should the agent (BDII) do when faced with stale data?  Should
> it simply log a warning or should it reject the data?
It should publish it.  Let the client figure out what to do with it.

I don't think 'Validity' is the right name, though. To solve your use
case, you need, IMHO, is a time estimate of when the next update of the
data will appear (or should have appeared).

A resource BDII which refreshes its data every 20 mins would put a
creation date of now() and a nextUpdate field of now()+20mins.

CASTOR at RAL actually have two different creation times because the
tape accounting is updated once every 24 hrs and the disk data every 2
hrs. Some StorageAreas would combine the two, so it'd be hard to give a
definite creation time and validty/nextupdate.

Cheers
--jens