1. Thoughts on the ATF of the DataGrid 24 th –25 th May 2001 Steve Fisher / RAL

2. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL2 Aim of this presentation Not about the ATF outputs but about how ATF has developed and how it functions Which aspects are worth copying What we did wrong.

3. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL3 Who are the ATF One person from each middleware WP One (two) person(s) from WP8-10 Brian Tierney – Consultant Ian Foster & Carl Kesselman – Consultants –Mostly by e-mail Dave Kelsey – Security –Recent addition Fabrizio Gagliardi Currently chaired by me

4. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL4 Why do we exist? We have no clear mandate We have no defined lifetime For the Amsterdam meeting I invented an informal mandate.

5. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL5 Why do we exist? – Amsterdam version 1.To define a viable architecture in terms of a set of components 2.To ensure that these are a useful set of components able to interwork to meet the (evolving) requirements 3.To alert the PTB to components that appear not to be fully covered by the various WPs. 4.For each deliverable, collect input from the WPs and produce a document showing the essential functionality. Inform the PTB if it appears that a component will not have the functionality required by another component. This led to us getting mixed up in management We are being asked to produce a dependency graph Will we do it for M21 and M33? 5.Make proposals to the PTB on certain technical matters. This has sometimes been controversial but is, I think, essential

6. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL6 Brief History A bumpy start last year –no one feeling responsible for making it work I started chairing the ATF in February. –The Amsterdam meeting was approaching and we had something to deliver There were plans to appoint an architect –but suitable candidate not found First DataGrid meeting in Amsterdam Planned to continue 1.5 days / 2 weeks –Hard to find free days with the frequency Joint session with the WP8-10 TWG Some of us participated in the ANL Globus meeting. Technical coordinator is about to be appointed? –Need to find right relationship with ATF

7. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL7 E-mail We communicate extensively by e-mail. Unfortunately a number of mail storms have been about the mailing list policy –ATF mailing list saga was bad –Problems with non-ATF members of the list(s) Some complained of too many mails Some complained that they were in the dark Some intervened and delayed us –Have experimented with various combinations of public and private lists Now we have one list with all ATF members and others who been asked to be added – but the extras are requested to send any comments via Fab or myself –This works!!!!

8. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL8 Plan to Amsterdam Produce model of system (UML) Define services – –then check if there is obvious mapping to an existing WP Write an architecture/design document based on Model Define month 9 functionality As we proceed various issues appeared and we try to make decisions both architectural and technical

9. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL9 First architecture document - Amsterdam First version of a document which defines the architecture of the EU DataGrid. –This is a large undertaking –Unlike other software projects we have worked on, many parts of the system are new (to us). – We are not just re-painting and re-assembling old components but planning to build something new. Consequently for now we can only describe what we see as a feasible architecture for the DataGrid. –The new components will have to be prototyped – some will just not work. The document will evolve during the lifetime of the project.

10. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL10 Life after Amsterdam After Amsterdam WP8-10 came back with a long list of criticisms of the architecture document. WP8-10 now working more closely with us to make sure that we produce something close to what is wanted Questions to ask WP8-10 –These questions will be those we need to be answered to help us put together the architecture. –3 sets so far

11. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL11 Beyond M9 It seems likely that we will continue to evolve the architecture As things get implemented evolution problems start – need to evaluate impact of proposed changes Meeting frequency and work load might reduce

12. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL12 Failures Too many criticisms of the first architecture document –Maybe this was inevitable. –WP8-10 had no requirements. –We wrote what looked good to us –Should have established better contact from the beginning – but – WP8-10 presence can also slow things down as they don’t stick strictly to requirements. Very hard to produce UML diagrams –All agree in principle with UML

13. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL13 Successes Identified some missing functionality and activities Got V1 of the architecture document out on time

14. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL14 Bad features No mandate No chair from the start The role of the experiment representative to the ATF not clearly defined All the middleware, experiment and security people must attend every meeting – no redundancy No architect

15. 24-25 May 2001DataGrid ATF - Steve Fisher/RAL15 Good features No architect –All members must have a vision Composition Meeting frequency (1.5 days every 2 weeks or so).