[ogsa-rss-wg] Candidate Ordering Language

[Soonwook Hwang]

> 
>       In order to deal with values that are expressed as xsd:dateTime
>       instead of numerics, value has an optional base attribute and the
>       result is the difference between the base time and the "value" time
>       in *seconds*.
> 
It's not clear to me about the idea behind the result returned
with difference between the base time and the "value" time in case
that the values are expressed as xsd:dataTime. Do you have some
usage cases about this?

> Example:
> 
> The value is the sum of the price times a constant factor, and the
> inverse square root of the number of CPUs allocated (using some schema
> for offers that I've picked out of the air)...
> 
>     <sum>
>       <product>
>         <value> //price/@value </value>
>         <constant> 42 </constant>
>       </product>
>       <power exponent="-0.5">
>         <!-- Assume that somewhere there's some JSDL -->
>         <value> //JobDescription/Resources/IndividualCPUCount </value>
>       </power>
>     </sum>
> 
> Or something like that. And this very simple structure has the advantage
> of being both pretty easy to implement (once you have XPath) and free of
> programming language nasties.
> 
> Is this sufficient? Or too complicated? Have I missed anything obvious?
> 
> (The other major alternative is to define a language that can compare
> two terms, but that's likely to be more difficult to do, and it can
> easily lead to ill-defined orderings, i.e. where there is no partial
> order on the offers at all. A scoring function doesn't have those
problems.) 

In general, I think I am fine with the language that you have 
come up with. However, I am wondering what it means to have 
as a returned ranking value the summation of the price (where dollar 
or completion time is likely used as its unit value) and the 
CPUCount (with the unit of CPU #). What dose it mean to sum
Momory size and CPU speed? 

Soonwook