perfsonar development work

[Loukik Kudarimoti <>]

Jeff W. Boote wrote:
> Loukik Kudarimoti wrote:
> > Hi,
> >
> > While testing out RRD MA (from perfsonar 1.0) and SQL MA (snapshot), 
> > I noticed that the response messages for a SetupDataRequest *without 
> > key* message does not provide a key back along with measurement data 
> > in the response. I remember that this wasn't the case some time ago.
> >
> > I support the idea of sending a key back for such requests. It allows 
> > us to say "Here is the matching metadata and data for your request 
> > and also, here is a key that you can use the next time you want data 
> > for the same metadata".
> >
> > Based on my experience, I believe including the key in the response 
> > requires a very minor change in the service engine code. All services 
> > implementing the key mechanism should similarly provide the key back 
> > for such requests.
> >
> > Any comments?
>
> This sounds reasonable to me.
>
> I would also add that the metadataid should be stable and unique. I 
> asked developers about a month ago how difficult that would be, and 
> have yet to hear a single response.
I can think of a few questions related to this topic.

a) What is the significance of having unique ids?
I am assuming that the ids need to be globally unique. For me, there is 
no question about ids having to be unique in a message or a store. Since 
I am not clear about the motive behind unique ids, I would appreciate an 
answer to this question.

b) What is the recommended structure of these ids (which one should 
follow in order to generate a unique id)? This question is important 
because clients such as viz. tools will need to generate these unique ids.

b) Is it necessary to confirm that the id is unique? If so, how do we go 
about doing that (rather, how can a program go about doing that)?

c) In the scenario where client X sends a request with certain metadata 
and data elements to Service A and Service A responds with metadata and 
data elements to client X
(i) If the service adds new metadata elements, the service generates the 
ids for these elements?
(ii) If the service modifies existing metadata or data elements, is it 
required to modify the ids as well?

d) Is it necessary to use unique ids for contents inside a store (i.e. 
metadata configuration files)?


Loukik.
> Silence equals agreement.
>
> jeff