perfsonar development work

[Roman Lapacz <>]

Jeff W. Boote wrote:
>  wrote:
> > If there is no data in the database the response will have only one 
> > datum element with 'UNKNOWN' values.
> >
> > example:
> >
> >
> >     <nmwg:data id="7f89" metadataIdRef="md-link-PSNC-2-DFN-MUE-004">
> >         <ifevt:datum 
> > xmlns:ifevt="http://ggf.org/ns/nmwg/event/status/base/2.0/";>
> >             <ifevt:stateAdmin>UNKNOWN</ifevt:stateAdmin>
> >             <ifevt:stateOper>UNKNOWN</ifevt:stateOper>
> >         </ifevt:datum>
> >     </nmwg:data>
>
> Roman - anyone else that was part of the decision to add this...
>
> Why is this better than no datum at all?
>
> My concern with adding this, is that it is different from the behavior 
> of other services now. The RRD-MA for example, returns no datum if you 
> ask for data outside of the time-range of data it holds.
>
> We want a generic visualization client to have only a very small 
> amount of work to add in each new data type. Therefore, we should have 
> as similar access semantics as possible for all MA's.
>
> If there is a good reason for it in this service, then it begs the 
> question: Should other services be creating the equivalent of a 
> 'missing-values' datum in the case of an empty result?

Hi Jeff,

I had similar concerns :) but I was asked by Loukik to do it (before the 
change there was no datum in the response). If I understood correctly, 
the visualization application made by JRA4 guys requires this approach. 
I'm sure Loukik can say more.


Roman