[dais-wg] Telcon Minutes from 17/05/05.

[Mario Antonioletti]

DAIS Telcon - 17/05/05
======================

Chair: Dave Pearson
Notes: Mario Antonioletti

Attendees:
----------

	Mario Antonioletti, EPCC
	Dave Pearson, Oracle
	Thomas Soddemann, RZG
	Susan Malaika, IBM
	Allen Luniewski, IBM
	Simon Laws, IBM

Agenda:
-------

o Session Planning for GGF14
o Object Data Access Realisation 

Actions:
--------

[Norman] Create a list of options for update of disconnected data sets.

[Simon]  Write up the top level IO operation to go in the core spec.

[Mario/Simon/Amy] Look at DAIS issue 1200 and either decide what needs
                  to done to resolve this and respond accordingly on
                  Grid Forge or flag it as an issue that needs to be
                  discussed at some future telcon.

[Mario] Continue working on the DAIS contribution to the data
        architecture.

[Susan] Look into how the XML attributes and elements for the resource
        properties relate to the DMTF CIM model.

-----

Thomas: posted a document on Grid Forge. 

       http://forge.gridforum.org/projects/dais-wg/document/WS-DAIO/en/
       (have to sign in to see this and possibly be a DAIS member).

	It's a start. Finding it difficult to find time. Need help to
	complete this for GGF14.

Pearson: what specific help? The specific issues in your mail?

Thomas: have ideas to bring into the document but would like other
	input. For instance on how to reference objects by web
	services - do not want to stick to one technology, e.g. WSRF.
	Later on may be able to match to WSRF.

Susan: there is a naming effort going on with OGSA - can use reference
       parameters. May want to look at that.

Thomas: that would be useful. 
        There is some kind of collection and that takes a naming
	schema and then we are done for the first draft.

Susan: how do you name your objects?

Thomas: the reference by itself is not a big deal but it's what it has
	behind it - an object has a state and a WS is usually
	stateless.

Susan: but that's why WSRF is there ...

Thomas: want to be a little bit more abstract to allow the use of
	other technologies .... could possibly use COBRA could be an
	implementation.  Also, have .Net. These would offer a state.

Dave: are you saying that a WS-I framework is not very appropriate for 
      you?

Thomas: yep.

Dave: Savas would say that there are ways of exposing state using 
      contexts.

Thomas: I should think about that.

Dave: Savas has always proposed that there are ways of doing this. The
      mapping's framework offers some ideas.

Susan: the business of passing names and state is part of the content of
       the mappings document.

Thomas: you leave it to the implementor to address the statefulness
	...  then you end up with implementations that are not
	interoperable.

Susan: the mappings document was just there to explore the space

Thomas: if you know the thing is stateful then you have to be more
        careful.

Susan: but this is true for relational and XML databases.

Dave: hopefully we can avoid exposing that state ...

Mario: do you have a use case in mind?

Thomas: if you get a reference to an object you are directly
	interacting with that object. In a relational model
	you are interacting with a result set, which may be
	a copy but may not be directly linked to the database.

	If you get the object out of the database - there is
	only one object regardless of the number of cases.
	You also have a number of links.

Dave: the result sets here is the output from a query. Whereas
      in an Object database the output is some data. Thomas
      is talking about manipulating the object itself.
      If you have an object that has several objects behind
      it then that is different from a view. 

      What state do you wish to expose Thomas? I can't find this in
      your document.

Thomas: talking about inheritance - gives different views on the same
	object. This has to be dealt with. A simple object, like an
	XML bean, then you have attributes that can be Set and 
	Get ... as an implementor you have to decide whether you
	expose a single object or expose multiple copies of objects.

*Simon joins*

Dave: a problem that Thomas is how you expose the state of an object
      ...

Simon: what do the interfaces look like? access to objects and
       collections of objects?

Thomas: yes ... there are ops like select and update where you get
	objects, there is also find where you get data, etc.

Simon: it's like the XML realisations where you have documents and
       collections and the response is a set of XML fragments - we
       might have to expand those ideas to deal with your objects
       ... is there any work of XML to object mappings? ....

Thomas: you can represent the state in XML.

Simon: we could adopt the mapping to get the state of an object ...
       is there any way of remembering the function of an object?

Thomas: it depends on the implementation of the object database -
	there are different kinds of data associated with an object.

Simon: there's still information about the type and its version 
       but not the functions that the object might support.

Thomas:in in principle you have the methods and the version - for
	  instance objects need to be serializable in Java.

Simon: sounds that something could be done like in the XML....

Thomas: have not thought about it that way. Originally started from
	the relational realisation and derived the object
	realisation. Could look at the XML spec .. sounds like a good
	idea.

Dave: in Oracle have something called toplink that might be of interest,
      Also Ajax may be of interest - useful documents in the IBM web
      site.

Thomas: Ajax is a web technology where java script is executed at the
        client side and loads XML from the server - is that it?

Dave: don't know if it might be useful...

Thomas: no, not if it's what I described as that is just a publishing
	technology.... 

       [want to give a third party (implementor, e.g.) the
	possibility to expose toplink and other proprietary O/R mapping
        technologies employing another namespace]

Mario: so you are just looking for ideas and asking for feedback...

Thomas: yes

Dave: Norman is the best person to deal with.

Mario: we could try to read the document and feedback to Thomas in the
       meantime.

...

Thomas: will have a look the XML spec to see if I can get ideas from
	that. If anyone else has additional ideas will be grateful for
	those. Also, would be grateful to get help to evolve the spec
	for GGF14.

Susan: the document deadline is the 27th May.

Thomas: will try to get the document into a better shape by then. 

Susan: should be ok to put in a preliminary draft.

Dave: yes, in particular if you have a list of known of issues

Susan: and any points you want to pursue and expand on ...

Thomas: there are comments that are not going to be the final document.

...

Dave: should get in touch with the CERN database group ... will email
      you with some names. They may have done some prototyping...

Thomas: we use objectivity ...

...

Dave: It might also be worth sending Norman an additional mail.

Planning for GGF:

Mario, Thomas, Dave will be there.
Simon not planning to go at this stage.
Expect Norman to go.
Susan not sure yet.
Amy is going.
Allen is doubtful as to whether he will be able to attend.

Dave: has any progress been made.

Simon: I don't think I should be the road block.

Mario: have not had time. Have not done much.

Susan: can we get an extension?

Dave: can send an email to Steve Crumb to see if we can
      get an extension. Probably the best I can do.

Susan: do Mario/Simon have half a day this week to discuss things.

Simon: I can do some time this week. Have been looking at the
       WSDL.

Mario: this week is fine, I'm off next week.

Simon: I'm unavailable next week. Have had effort promised from Paul
       and Malcolm to get review time if we get something ready.

Mario and Simon will get together to try and do something.

Dave: hope to do two sessions at GGF to cover the different specs.
      Half session for objects and one a half sessions to present the
      other material.

Susan: ok.

*Discussion regarding what we should not clash with DAIS*

Simon: if we can come out of this week with the WSDL then that allows
       progress to be made.

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|Mario Antonioletti:EPCC,JCMB,The King's Buildings,Edinburgh EH9 3JZ.   |
|Tel:0131 650 5141|mario at epcc.ed.ac.uk|http://www.epcc.ed.ac.uk/~mario/ |
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