perfsonar development work

[Jason Zurawski <>]

Roman;

> > > Hmm, but a key can represent a chain of metadata. This is my 
> > > understanding of a key (something which is just an id; it does not 
> > > matter how it looks like; I could imaging that a service could have 
> > > a map structure with pairs key - metadata chain ).
> > Thats not entirely true, a cooked key gives you access to the 
> > combined effects of the end of a chain of metadata.  The important 
> > thing to remember here is that a chain is constructed with an 
> > *explicit* ordering to get some specific data (i.e. first grab the 
> > entire data set, then run a filter chain on time, then perhaps do a 
> > CDF):
> >
> > <nmwg:metadata id="1">
> >  <nmwg:key>
> >    <nmwg:parameters />
> >  </nmwg:key>
> > </nmwg:metadata>
> >
> > <nmwg:metadata id="2">
> >  <select:subject metadataIdRef="1"/>
> >  <nmwg:eventType />
> >  <select:parameters />
> > </nmwg:metadata>
> >
> > <nmwg:metadata id="3">
> >  <cdf:subject metadataIdRef="2"/>
> >  <nmwg:eventType />
> >  <cdf:parameters />
> > </nmwg:metadata>
> >
> > <nmwg:data id="d1" metadataIdRef="3" />
> >
> >
> > Your current cooking procedure should give something like this (?):
> >
> >
> > <nmwg:metadata id="k1">
> >  <nmwg:key>
> >    <nmwg:parameters />
> >    <select:parameters />
> >    <cdf:parameters />
> >  </nmwg:key>
> > </nmwg:metadata>
> In my implementation both solutions are possible to use: 1) only a key 
> in the request with all parameters (for example: nmwg + select) or 2) 
> a chain where the root is a metadata with a key (as you presented in 
> the first example above). If the order is important then the latter 
> solution should be used. That's right.
>
> This is one of my example request that I use to test java rrd ma:


<snip />


> So I'm not against want you prefer but I allow to use also only a key 
> as a container for all stuff where the order is not important.


It would be far less ambiguous to alway assume order matters, this will 
cut down on corner and special cases.  Like I said previously, this 
isn't an issue yet but it will be as more complex services come online 
it will be.  For the short term this just needs to be a 'think about it' 
task, but after things calm down it should be examined again in detail.


-jason