1. Matthew Palmer, Cambridge University01/10/2015 First Use of the UK e-Science Grid Overview The Physics Experiences Looking forward Conclusions Matthew Palmer, Cambridge University

2. 01/10/2015 Physics Generated 150 million background events using Herwig event generator and the ATLAS fast detector simulator Produced useful physics Used >1000 CPU hours in real time of <24 hours Total of ~100 CPUs in 6 clusters at 5 institutions Used only the standard Globus tools This initial use of the Grid was a success – but took a lot of work

3. Matthew Palmer, Cambridge University01/10/2015 The Grid Experience Libraries Side-stepped this issue by compiling my program statically – but this isn’t always possible and in any case, removes the advantages of using libraries. User accounts I had to apply to each institution individually for user accounts on their machines. If I have an account there, why do I need the Grid? Firewalls Some institutions require that connecting machines be explicitly added to their firewall list. This adds to bureaucracy. System Administrators Were really helpful! They modified configurations and added services at my request. Dynamic Information Currently hard to get information on loads, queue lengths etc.

4. Matthew Palmer, Cambridge University01/10/2015 The Grid Experience cont. Configuration issues Many sites had configuration issues when I first used them – hopefully these have been resolved and will be picked up as more people start to really use the Grid. Homogeneity Most sites had slightly different configurations e.g.:  limited quotas in the home directory  Particular environment setup (for firewalls etc) GridFTP Far superior way of transferring files compared to globus-url-copy Remoteness Hard to be precise, but using the Grid ‘feels’ very remote. This has a serious impact on productivity and ease of use. Fortunately, tools like gsincftp help overcome this. GSISSH would be very useful as well.

5. Matthew Palmer, Cambridge University01/10/2015 Looking Forward Advanced Features It would be nice to have features like load balancing, job-tracking etc Middle-ware essential to get the most out of the e-Science Grid Good middle-ware would fix many of the issues I’ve raised and improve the scalability of the e-Science Grid. Would EDG software be suitable? Not for me to decide! But maybe you can help. Globus software will remain the lowest common denominator It is likely that there will be no middle-ware standard for some time. So, any program that can be run using just Globus software will be more widely useable. To this end, Frederique Brochu has had some success in running the ATLAS software on plain Globus.

6. Matthew Palmer, Cambridge University01/10/2015 Conclusions Level 1 Grid can be used to do physics  At the stage where, with education, a colleague was able to use the Grid for his own work relatively painlessly. But  it isn’t scalable beyond about 10 sites  Can feel remote and thus is not user friendly – doesn’t encourage take-up Need for middle-ware  Maybe EDG software – can GridPP help?