Leicester: WPA1/WPA0: Architecture Focus Meeting

Draft Minutes 3 March 2002 by NicholasWalton

Present: Nic Walton (NAW), Tony Linde (TL), Guy Rixon (GTR), Clive Page (CP), Bob Mann (BM), John Sherman (JCS) (after 14.20)

Time: 13.00-17.00

1. Talking through the agenda as posted on the wiki page. TL noted that the layer diagram was only in a draft form and was open to amendment.

TL noted that ACTIONS, except where specified, are for completion by the end of Q3 (e.g. 31 May 2002).

2. TL indicated that Q3 work would still be largely design and research work. GTR stressed that any prototypes developed in this period will not be final, and therefore the interfaces are liable to change.

3. Science and User cases:

WPA1. Abstraction of science and user cases: process is to scope the current full set in the VO wiki, and determine which are relevant to the priority data sets for the 3 yr project. these then become the Astrogrid set of cases.

ACTION NAW by 20020322

4. WPA1. Activity diagrams (= flow chart) - NAW to talk to the person responsible for that case area - talk through it. NAW and that WP manager would together generate the relevant flow diagram. (NAW needs to make sure that there is sufficient text info associated with each science/user case.) NAW needs to identify high priority data sets for AstroGrid in Phase-B, and note where they are held (or distributed from).

ACTION NAW by 20020322

5. WPA2. In order to specify the client manager we need to know how data is specified and accessed. Anita Richards will be asked to look into this. Starting point is CP's paper (shortly to be posted on the Wiki) on existing VO prototypes.

ACTION TL by 20020320: ask Anita Richards to generate this report

Object models, component and implementation diagrams (OCI) for Level 3. GTR - need to see a web service prototype with Globus installed. (relevant for tools and functions services in L2).

ACTION GTR by 20020531: Prototype a computation on one or more grid nodes (e.g. some Iraf tasks). Deploy and run a computation intensive process on the grid.

6. VO interface - GTR needs to look into whether or not WSDL is appropriate at the higher levels.

GTR is going to rewrite the layer diagram (check Wiki for updates) - refactoring the top part of the diagram to break down what is in the browser and what is in the server.

ACTION on ALL - draw up a plan of what they are doing and planning for Q3 - quarterly forecasts by March 8, March 6 for the reports.

Part of WPA2: look at where jobs will be run (job optimisation services in the VO services block). whole issue of estimating run times, does the user want to proceed with the job - idea of monitoring jobs.

JCS: there is a worry about that are the boundary conditions on the architecture. We need to be using existing technologies where possible. CP/TL noted that we were endeavouring to do just this.

JCS: when do we talk to the data centres about they will interface with the AstroGrid system?

It was agreed that it was not sensible to discuss this with the data centres as a whole until Phase-B of AstroGrid was better specified. Thus TL would re-visit this question in Q4. TL/NW did note though that many of the archive centres that AstroGrid would interact with in Phase B were in fact already members of the AstroGrid consortium.

CP noted that AstroGrid could offer useful capabilities to data centres in the area of authorisation/ certification.

GTR/JCS; a design review of the architecture will be needed to ensure that it will meet the demands of the use cases which are defining it. it was AGREED that this will happen at the next AstroGrid Collaboration meeting that should be held in June 2002.

ACTION TL: fix dates and set up a Collaboration meeting for the week starting 24 June 2002.

7. WPA4 - CP wondered how does this work fit into other work being done outside of AstroGrid, or in partnership with AstroGrid: e.g. Interoperability work withing Opticon/AVO.

NW asked what is the status of the VOTable proposal. Does WSDL supersede it? No, VOTable holds the XML descriptors.

ACTION CP: Before generating an OCI for data access, WPA4 will make a proposal for the data query language which will be exposed by the data access web services. (The discussion focused on VOTable and xquery.)

Part of WPA4 will include the development of a runtime estimator, perhaps located in Level 1 of the Layer diagram.

BM noted that SX issues run time estimates - but it only knows about the time needed to complete a query on the database. This doesn't take account of distributed databases, speed of networks etc.

8. WPA9: draft designs for Level 4: client and browser based UI. JCS noted that this could use the WPA5 pilot matching optical and X-ray data as setting the requirements for a first pass prototype.

WPA9 will assess how runtime estimates/feedback from runtime monitoring etc will be integrated into the UI.

9. Research:

ACTION JCS: WPA3: assess how the proposed OGSA initiative can be integrated into the AstroGrid architecture.

ACTION CP: WPA4: assess Grid initiatives (e.g. DBTF) and their likely impact in the area of data mining.

10. Technical approach for product development would be addressed by the Technical working group.

11. TL, through WPA0 would specify AstroGrid Phase-B (by end Q3)

12. Prototypes to be developed in Q3

1. JCS: WPA9: user interface, browser and client
2. GTR: WPA2: certification, authentication and authorisation system
3. GTR: WPA2: limited resource directory (the two WPA2 prototypes might be combined into one).
4. Elizabeth Alden: WPA2/5: a web service interface to access a data set
5. GTR: deploy and run a computational module on a grid machine (see 5.)

13. There was some discussion as to the main risks associated with Q3 work. The risk, the probability of occurrence, and its impact if it did occur were noted. Where appropriate a workaround was identified.

Meeting closed at 17.00

-- NicholasWalton - 02 Mar 2002

The actions from his meeting should be taken to include those listed in the agenda, particularly the OCI diagramming, unless specifically revoked above.

-- TonyLinde - 18 Mar 2002