perfsonar development work

[Roman Lapacz <>]

Jeff W. Boote wrote:
> Roman Lapacz wrote:
> > Guilherme Fernandes wrote:
> >
> > > Loukik Kudarimoti wrote:
> > >
> > > > Hi,
> > > 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?
> > > >
> > > > Loukik.
> > >
> > >
> > > But we also have the situation where the data in the response 
> > > belongs to many keys (this is often the case when fetching OWAMP 
> > > data from the SQL MA, like getting all the data that belongs from a 
> > > src to a dst). You could return all the keys that are related, but I 
> > > think you can't request data passing multiple keys (at least in the 
> > > current implementation, but I could be wrong).
> >
> >
> > You can, just use more than one data trigger in the request and then 
> > you can fetch more than one data set.
> >
> > But how we can link two metadata elements, one with the key and the 
> > second with meta (for example interface element), in the response 
> > with data? Chaining, I guess. But this complicates things.
>
> This was done in the code you removed from the RRD MA last year Roman. 
> That is exactly why it was more complicated before.


Please, show me an example of such response (metadata + metadata with 
key + data). I just want to see how the elements are linked.

Roman