[OGSA-BES-WG] BES question

[Joseph Bester]

On Mar 15, 2007, at 7:33 AM, dejw wrote:

> Hi,
>
> maybe some example what I meant so far:
>
> The case is when I get ActivityIdentifier from BES service which is as
> the BES schema says:
>
>  <xsd:element name="ActivityIdentifier"
>     type="wsa:EndpointReferenceType"/>
>
> and wsa:EndpointReferenceType is:
>
>
>     <xs:complexType name="EndpointReferenceType" mixed="false">
>         <xs:sequence>
>             <xs:element name="Address" type="tns:AttributedURIType"/>
>             <xs:element name="ReferenceParameters"
> type="tns:ReferenceParametersType" minOccurs="0"/>
>             <xs:element ref="tns:Metadata" minOccurs="0"/>
>             <xs:any namespace="##other" processContents="lax"
> minOccurs="0" maxOccurs="unbounded"/>
>         </xs:sequence>
>         <xs:anyAttribute namespace="##other" processContents="lax"/>
>     </xs:complexType>
>
> So as you can see I can have always Address so uri of target service,
> and its ok here. But the problem is with 'ReferenceParameters'. The
> definition of this is:
>
>     <xs:complexType name="ReferenceParametersType" mixed="false">
>         <xs:sequence>
>             <xs:any namespace="##any" processContents="lax"
> minOccurs="0" maxOccurs="unbounded"/>
>         </xs:sequence>
>         <xs:anyAttribute namespace="##other" processContents="lax"/>
>     </xs:complexType>
>
> So it can contain any xml blob. And many BES services have their  
> own xml
> here inside it. So I as a programmer have to parse these xml's and get
> the job id which is always some string and that's all.
> So I think this xml is useless here unless it is common for every  
> service.
>

The endpoint reference type is a web services standard way of  
describing how to contact a web service, potentially including  
references to some state managed by the service via the  
ReferenceParameters (these are similar in concept to http cookies).  
The ReferenceParameters are to be considered an opaque data block to  
service clients.

There is no guarantee that any sort of meaningful local identifier  
will be present in the EPR. It is meant to be used by the Web Service  
hosting system to  address  Web Service operation requests to the  
particular stateful resource associated with the created activity.

> Now I have to now what "type" of underlying system I have i.e. crown,
> unicore, gridsam etc. and then I have to built a little different
> ActivityIdentifier to get job status for example. It's a little  
> strange.

The EndpointReferenceType can be sent in the body of the  
GetActivityStatus operation directly. Why do you think you need to  
know about the contents of the EPR?


joe