[Fwd: Re: [seek-dev] Ecogrid/Digir Transform Question]

Dave Vieglais vieglais at KU.EDU
Wed Feb 11 09:14:04 PST 2004


I just noticed that this was sent to Rod only instead of the list:

-------- Original Message --------
Subject: Re: [seek-dev] Ecogrid/Digir Transform Question
Date: Wed, 11 Feb 2004 00:16:08 -0600
From: Dave Vieglais <vieglais at ku.edu>
To: Rod Spears <rods at KU.EDU>
References: <401EA1FB.9080205 at ku.edu>

Rod Spears wrote:

> A Digir Query has a "destination" tag that is rather important for
> directing where the query the should be executed (and includes the
> "resource"). An example is below. Where would the dest info be "coded"
> in an EcoGrid Query destined for Digir? In the metadata?
>
> Rod
>

My recollection is that the intended implementation of the EcoGrid query
interface is that there is a one to one correspondence between a query
interface instance and a data resource.  Hence there is currently no
concept of multiple data resources being exposed through one ecogrid
data service that supports a query interface.

This is contrary to the situation with DiGIR where a data provider
service can support multiple data sources.  That is the reason for the
resource attribute of the destination element.  The intended enpoint is
included in the destination to support the possible role of data
providers acting as proxies to other data providers.

I believe the intent during the design of the ecogrid interface was that
it would be trivial to append an attribute to a service url, and so
effectively create a new instance as far as the ecogrid was concerned:

http://some.server/query.jsp?source=1
http://some.server/query.jsp?source=2

Where source indicates a different resource being exposed by the query
interface instance.

After talking with Rod yesterday, it seems that this solution is
unwieldy when working with Globus, and it is suggested that a more
appropriate solution for that environment would be to add an attribute
to the ecogrid query request document that indictated the intended
resource.  This would add very little overhead to the interface on
metacat and would improve the utility of the ecogrid interface for
accessing DiGIR resources.

Let's resolve this in the telecon later today.

cheers,
   Dave V.



> 
> <request
>     xmlns="http://digir.net/schema/protocol/2003/1.0"
>     xmlns:xsd="http://www.w3.org/2001/XMLSchema"
>     xmlns:darwin="http://digir.net/schema/conceptual/darwin/2003/1.0"
>     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>     xsi:schemaLocation="http://digir.net/schema/protocol/2003/1.0 
> http://digir.sourceforge.net/schema/protocol/2003/1.0/digir.xsd 
> http://digir.net/schema/conceptual/darwin/2003/1.0 
> http://bnhm.berkeley.museum/manis/DwC/darwin2jrw030315.xsd">
>     <header>
>             <version>1.0</version>
>             <sendTime>2003-03-09T19:14:58-05:00</sendTime>
>             <source>127.0.0.1</source>
>             <destination 
> resource="MammalsDwC2">http://manis.mvz.berkeley.edu/DiGIRprov/www/DiGIR.php</destination>
>             <type>search</type>
>     </header>
>     <search>
>             <filter>
>             <and>
>                 <like>
>                     <darwin:ScientificName>peromyscus 
> man%</darwin:ScientificName>
>                 </like>
>                 <notEquals>
>                     <darwin:DecimalLatitude>NULL</darwin:DecimalLatitude>
>                 </notEquals>
>             </and>
>             </filter>
>             <records limit="10" start="0">
>               <structure>
>                 <xsd:element name="record" 
> xmlns:xsd="http://www.w3.org/2001/XMLSchema">
>                    <xsd:complexType>
>                       <xsd:sequence>
>                          <xsd:element ref="darwin:ScientificName"/>
>                          <xsd:element ref="darwin:Latitude"/>
>                          <xsd:element ref="darwin:Longitude"/>
>                       </xsd:sequence>
>                    </xsd:complexType>
>                 </xsd:element>
>               </structure>
>             </records>
>             <count>true</count>
>     </search>
> </request>
> -- 
> Rod Spears
> Biodiversity Research Center
> University of Kansas
> 1345 Jayhawk Boulevard
> Lawrence, KS 66045, USA
> Tel: 785 864-4082, Fax: 785 864-5335
> 





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