July 2011 - nml-wg - lists.ogf.org

Session notes for NML
by Freek Dijkstra 29 Aug '11

29 Aug '11

Members of the NML working group joined for two sessions at OGF 32. About 15 participants attended the sessions. Here are some notes; note that they are not complete (Jerry created some additional notes during the 1st session). However, I'll post them here now before I forget... :) At the first session, Jeroen van der Ham went through the RNC schema, explaining and correcting minor issues. The main topic on the table was the XML syntax for describing ordered lists. After some heated discussions, the participants agreed on the following syntax for an example of a link "link_A-to-C" is described as the concatenation of two smaller segments, "link_A-to-B", followed by "link_B-to-C". <nml:link id="urn:ogf:network:example.net:link_A-to-C"> <nmlserialcompound:relation type="serialcompound"> <nml:link idRef="urn:ogf:network:example.net:link_A-to-B"> <nml:relation type="next"> <nml:link idRef="urn:ogf:network:example.net:link_B-to-C" /> </nml:relation> </nml:link> <nml:link idRef="urn:ogf:network:example.net:link_B-to-C"> </nml:link> </nmlserialcompound:relation> </nml:link> A few notes are in place here: * As agreed earlier, the syntax does not rely on the order of the XML elements in the syntax (while most parser retain the order, this is not required by the XML specification.) Indead, the "next" relation is used to explicitly specify the order. * No explicit "first" or "last" element is specified. A "last" element in a list can be found by finding the item without a "next" relation. A "first" item in a list can be found by finding the only item in the list which has no pointer to it. * There can be only one "first" and "last" element in a list; this means that branching (e.g. an item with two "next" items) is not allowed; this should be described with another construct. * This means that * while it was argued that the "next" relation is a syntax construct, while the relations as defined in the NML UML schema are topology constructs, and thus different, the same syntax would be used to describe both relations. * The name of the topological relation in the above example is called "serialcompound" after Figure 10 of G.805 (of Figure 16 of G.800). The name was not great, but the participants were too tired to come up with something better :) * The ordered list on itself is not enclosed in it's own XML tag (like <nml:list>), the elements are direct subelements of the parent <relation> tag. * At the end of the session, the participants had a discussion how to encode the relation type. In the above example, it is listed as '<nmlserialcompound:relation type="serialcompound">' and '<nml:relation type="next">'. While some arguments where laid forward, no definitive conclusion was reached. This topic remains open for discussion>. Finally, I like to thank all contributors to the discussion. It may have taken some time to talk some sense in me, that was due to my stubbornness, not due to the quality of the arguments. Those were in my opinion particularly good. A particular thanks to Jeff, Jason and Jeroen (the 3 J's) is certainly in place. Thanks, Freek

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XML syntax for NML relations
by Freek Dijkstra 16 Aug '11

16 Aug '11

Hi all, Let me follow up on a technical part of yesterday's discussion. > At the end of the session, we had a discussion on how to encode the > relation name (here: "serialcompound") in XML. E.g. each relation as > a different element, a different attribute, or a different value of a > fixed attribute. So far, the relation type is encoded in the value of a type attribute (e.g. <nml:relation type="serialcompound">). Freek pointed out that this makes it harder to create a meaningfull schema for validation. For example, there is a difference syntax associated with next relations and serialcompound relations. <nml:relation type="serialcompound"> may contain 0 or more children, while <nml:relation type="next"> must contain exactly one child. The RNC schema does provide a means to specify this difference. Jeff confirmed this and pointed out that it is of course still possible to check the syntax using other logic, it is just not possible to create a detailed schema. (Freek pointed out that NMC has the same problem, which is the reason that no non-trivial WSDL was created for perfsonar, and no software used a SOAP library, despite that most NMC messages are embedded in a SOAP envelope). The encoding of the type of relation in a element (e.g. <nml:serialcompound>) allows more meaningful validation. However, this has another drawback: if a client does not know about a particular relation, it does not know if the unknown element is subclass of a relation and can or can not be ignored. In fact, it can not even do basic syntax checking (as if it was just a unknown NML relation), since it does not know it is a NML relation without parsing the schema definition (which will list the new element as a subclass of the base element). So there seem to conflicting requirements: * ability to do extended validation * know from just looking at XML (but not the schema) that something is a NML relation It may be possible to find a solution that caters to both requirements. For example, in NM, subclasses use the same name (a trick known as chameleon namespace in RNC). E.g. A subclass of e.g. http://schema.ogf.org/nm/base/port is also called "port", e.g. http://schema.ogf.org/nm/layer2/port. A similar trick is enforce that all relations must always be defined in the same namespace (which may only contain relations). E.g. everything that starts with http://schema.ogf.org/nml/relation/ is a relation. I think we should discuss this further. I know the above is a difficult technical discussion, so I appreciate that you read so far. Please provide feedback if this was clear, and if you have any opinion or thoughts on this topic. Regards, Freek

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Examples for discussions
by Freek Dijkstra 15 Jul '11

15 Jul '11

If you attend the NML session today, you may want to download the file "Proposed XML examples" at http://www.ogf.org/gf/event_schedule/index.php?id=2296 Regards, Freek

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Notes from 30 june conf call
by Freek Dijkstra 14 Jul '11

14 Jul '11

NML conference call June 30, 2011 participants: Chin Guok Aaron Brown Jason Zurawski Jeroen van der Ham Freek Dijkstra OGF32 participants Chin Guok Jason Zurawski Roman Łapacz Jeroen van der Ham Freek Dijkstra (only Friday and Saturday morning) Martin Swany will not be able to make it. NSI: most likely Tomohiroh, Inder, Guy Likely not: Jerry Sobiesky, John McAuley. Activities Jeroen create a visual OWL editor. OWL is an more expressive RDF variant, with more restriction (eg distinction between data and classes) It is not handling the ontology perfectly, trying to improve that. Easy to make examples. Aaron tried it briefly. Action list: Freek: make improved examples. OGF presentations: Aaron slides on Circuit Monitoring, presented by Jason Jeroen/Freek/Roman Łapacz on RNC schema make picture, go through it step by step We will meet Friday 9.00 o'clock near the OGF registration desk to see if we can start discussion, even though the conference will only start in the afternoon.

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Fwd: [I2-NEWS] Internet2 and Open Grid Forum announce Workshop on Science Agency Uses of Clouds and Grids
by Jason Zurawski 06 Jul '11

06 Jul '11

All; FYI for those that didn't see this, it will take place all day Monday of OGF 32. Lots of interesting stuff happening in this area, for those that wish to attend. Thanks; -jason -------- Original Message -------- Subject: [I2-NEWS] Internet2 and Open Grid Forum announce Workshop on Science Agency Uses of Clouds and Grids Date: Fri, 1 Jul 2011 15:03:11 -0500 From: Alan Sill <Alan.Sill(a)ttu.edu> To: i2-news(a)internet2.edu <i2-news(a)internet2.edu> *Workshop On Science Agency Uses Of Clouds And Grids Announced* Muncie, Indiana; July 1, 2011 - The Open Grid Forum <http://www.ogf.org> and Internet2 <http://internet2.org> today announced a new workshop titled, "Science Agency Uses of Clouds and Grids <http://www.ogf.org/SAUCG/>" to be held in Salt Lake City, UT on July 18, 2011. The workshop is a follow-on to the previous USDOE-sponsored workshop on High Performance Applications of Cloud and Grid Tools <http://www.ogf.org/HPACG> held in April, 2011. This workshop will serve as a venue to develop formal input to several ongoing standards and software roadmapping efforts, including the European SIENA Cloud Standards Roadmap <http://www.sienainitiative.eu/> project and the US National Institute of Science and Technology's Cloud Computing Business Use Cases <http://collaborate.nist.gov/twiki-cloud-computing/bin/view/CloudComputing/B…> group, as well as to OGF's own standards efforts <http://www.ogf.org/standards/>. International contributions to this workshop are encouraged and will be accepted. Project status updates on cloud and grid framework software efforts and major projects are recruited to be presented at this workshop. The primary goal of this effort will be to produce a process that will effectively inventory and document essentially all large-scale use of cloud and grid infrastructures for projects that support science agency user communities. The schedule will consist of an introduction to the goals of the above roadmapping efforts presented by representatives from these projects and from the workshop sponsors. Materials relating to the inventory aspects of this effort are in preparation and will be distributed before the meeting. Workshop time will be taken in the morning session to present materials gathered to that point and to recruit and gather further information from workshop participants, and to go over the gathered material for completeness. The afternoon session will be devoted to presentations from projects that have not already presented at the previous HPACG <http://www.ogf.org/HPACG> workshop. Special presentations from the Open Science Grid <http://opensciencegrid.org/> on how to create a new Virtual Organization <http://www.opensciencegrid.org/About/Getting_Started_with_OSG/Form_New_VO> and a preview of the upcoming evolution of the Teragrid project into the eXtreme Digital <https://www.teragrid.org/web/about/XDTransition> era by representatives in attendance are anticipated. A special presentation on the Globus Online <http://globusonline.org/> service and other projects of the Globus group will also be made. Time for other special presentations may also be available; please contact the organizers <mailto:standards@ogf.org>. This workshop is co-sponsored by the US National IT R&D Large Scale Network (LSN) Middleware And Grid Infrastructure Coordination (MAGIC) Team <http://www.nitrd.gov/subcommittee/lsn/magic/>, Internet2 <http://internet2.org/> and the US Department of Energy <http://energy.gov/> with funding from the US DOE Office for Advanced Scientific Computing Research <http://science.energy.gov/ascr/>. To register or for more information, visit: http://www.ogf.org/SAUCG/

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