perfsonar development work

["Jeff W. Boote" <>]

 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?

jeff