1. Experiences with the Globus Toolkit on AIX and deploying the Large Scale Air Pollution Model as a grid service Ashish Thandavan Advanced Computing and Emerging Technologies Centre

2. Outline eMinerals project OGSA Testbed project Air Pollution Model Air Pollution Model as a grid service GT3 on the IBM Air Pollution Model as grid service (again) Current status & Future work

3. Our IBM pSeries parallel computer Four IBM pSeries p655 nodes each with Eight 1.5 GHz POWER4 processors 16 GB RAM 2 x 36 GB internal storage Private Gigabit ethernet AIX 5.2 and SLES 8.0 (dual boot) IBM C, C++ & Fortran compilers, IBM’s POE & LoadLeveler scheduler

4. Environment from the Molecular Level Using molecular simulation techniques to investigate fundamental problems associated with key environmental issues such as nuclear waste storage, pollution & weathering Researchers & resources from 7 UK institutions Funded by NERC www.eminerals.org

5. eMinerals minigrid

6. OGSA Testbed Test and evaluate the first implementation of the OGSA core by installing the GT3 toolkit on a service-based grid testbed spanning organisational boundaries Deploy a set of applications on this testbed as grid services & document experiences 5 project partners & 2 associate members Funded by EPSRC dsg.port.ac.uk/projects/ogsa-testbed/

7. Applications from Reading Phylogenetic Tree Construction – Sequential & parallel (MPI) versions in C – Runs on clusters & on IBM machine Large Scale Air Pollution Model – Only parallel implementation (MPI) in Fortran 77 – Runs only on IBM machine

8. Air Pollution Model Developed by the Danish National Environmental Research Institute (NERI) Mathematically represents interaction of physical & chemical processes : – Horizontal transport – Horizontal diffusion – Chemical transformations due to emissions – Deposition of pollutants to surface – Vertical exchange

9. Air Pollution Model Physical and Chemical Processes System of Partial Differential Equations Splitting procedur e Horizontal Transport Horizontal Diffusion Chemistry & Emissions Deposition Vertical Exchange Horizontal Transport & Horizontal Diffusion Vertical Exchange Chemical Reactions & Emissions & Deposition

10. Running the Air Pollution Model Hundreds of Fortran 77 programs organised logically into sub-directories (each a module) Makefile provided; compiler xlf_r is used A ‘ main ’ directory contains executable & configuration file (with initial input params) Loadleveler job submission file calls poe with appropriate parameters

11. Air Pollution Model as Grid Service IBM machine has GT3 installed 1. APM available as a grid service that clients talk to 2. APMGS invokes MMJFS 3. MMJFS submits job to LoadLeveler … ideal scenario!! Client Internet IBM Resource

12. GT3 on the IBM machine A non-starter…. GT 3.0.2 – didn’t build successfully… GT 3.2beta – didn’t build successfully… GT 3.2.1 – didn’t build successfully… Different compilers ( xlc, gcc ) & ‘ flavor s’ ( cc [ dbg ][ pthr ])

13. GT3 on the IBM machine NSF Middleware Initiative provided pre- compiled binaries of GT3.2.1 for AIX 5.2 Release notes of latest version (5.1) confirmed problems with – globus_grim (due to which container cannot be started) on AIX – MMJFS on AIX – Other minor issues

14. Possible solution GT3 installed on intermediary Accepts client requests Performs authentication & authorisation Mediates job requests between client and IBM resource Client Internet Globus gatekeeper IBM Resource

15. Air Pollution Model as a grid service - job submit, cancel, hold, release, etc. 3 Globus Machine Client Local LAN IBM Resource 5 6 7 8 BA 1 4 2

16. Air Pollution Model as a grid service - job and system status monitoring 3 Globus Machine Client Local LAN IBM Resource 5 6 7 8 BA 1 4 2 D C 9 1011 12 13

17. Constituent parts Three parts to this solution 1. Grid Service 2. Server – resource communication Job submission, hold, release, cancel Job & system status 3. Client Interface

18. Current status Resource communication – Job submission of simple commands implemented – Job & system status under development Grid service part partially implemented Command line client interface (developed & used mostly for testing the other parts)

19. Future Work Generic RemoteResourceJobService – will support different schedulers like Condor, PBS, SGE, LSF, etc WSRF implementation of the grid service Option to encrypt server-resource traffic Client interface - portal & application versions XML messaging, more robust

20. Dziękuje!! Proszęo Pytania?