1. XtremWeb: Building an Experimental Platform for Global Computing Gilles Fedak, Cécile Germain, Vincent Néri, Franck Cappello Université Paris Sud, LRI, FRANCE Parallel Architecture Team « Cluster and Grid » group

2. Outline l Motivations and Goals for XtremWeb l Use example and applications. l Inside XtremWeb. l Conclusion.

3. XtremWeb Objective A platform to investigate Global Computing and Peer to Peer system issues Using PCs connected to Internet during their idle time X * 1000 volunteers PCs XtremWebWork Server LRI XtremWeb Result Collector LRI? Internet

4. Global Computing l Massively Distributed Applications –SETI@Home, distributed.net –2.5 Millions users, 30 TFLOPS l Research Projects –Javelin, Bayanihan, JET, Charlotte l Ongoing Projects –Entropia, Parabon, Peer to Peer WG –Folding@Home, Xpulsar@Home Global Computing : cycle stealing on a very large number of unused computing resources over Internet.

5. Peer to Peer l Massively distributed applications –Napster, Gnutella, Freenet, etc. –Large number fo users ~x Millions, Stockage area in the TeraByte order l Research Projects –Globe (Tann.) Cx (Javelin), OceanStore (USA) XtremWeb (LRI) –AppLeS (UCSD) l On going projects –Cosm, Wos, peer2peer.org, Jxta P2PTL (Intel) CoG (Globus). l Conference –O’Reilly l Book –Peer to Peer, « Harnessing the Power of Disruptive Technologies » Andy Oram, O’Reilly Peer to Peer : Global Client/Server resources and services sharing over Internet.

6. Desired Properties. l Computing models. –Global Computing. –Peer to Peer. l Multi-applications –Native code execution. –Worker safety. l High performance –Scalable and dedicated server. –Multi protocol communication. l Open source –For research on global computing. –Multi-disciplinary, for production by the mean of global computing.

7. Architecture l Global Computing and Peer to Peer l 3 entities : client/server/worker l Centralized (hierarchic) PC Worker Internet or LAN PCs Server XW Global Computing (client) PC Worker PCs Server XW Peer to Peer PC Client GC Model PC Worker P2P Model PC Client/Worker

8. Application example: Pierre Auger Observatory Project AUGER: Understanding very high energy cosmic rays (10 20 ev) Physicists are unable to reproduce them on earth. 1 rays every century per Km2. Possible origin : galaxies collision.  building 2 very large detectors in south and north America  simulate a huge number of rays entering the atmosphere (air showers) and compare them with detectors measurements. Aires application needs a considerable computing power to calculate a very large set of independent simulations

9. l Aires: Air Showers Extended Simulation –Monte Carlo, Sequential, Multi parameters –time for a run 5 to 10 hours PC worker Aires PC worker air shower PC server Internet Application example: Pierre Auger Observatory

11. Worker Interface –volonteers can evaluate their contribution to the computing effort. Application example: Pierre Auger Observatory

12. Another application example: Peer to Peer Ray Tracing Peer to Peer PovRay: Using the standard PovRay program (unmodified) Goal : Anyone can submit a scene and obtain the resulting image. PC Client/Worker PovRay PC Server PovRay Ray tracing service PC Client/Worker PovRay Internet or Intranet PovRay installed on every computer

13. Multiple Workers Protocol l Workers Initiate Transactions Worker registers to server with hostRegister. When unused, worker emits getWork. Server sends parameters of the task. While computing, worker emits workAlive Server manages timeout on workAlive At the end of the computation, worker sends back its results trough workResult Worker Server WorkRequest workResult hostRegister workAlive

14. Worker Architecture l Screen saver for desktop computer l CPU Activity for nodes of processors farm Thread Activity Monitor Control Thread Activity Monitor Thread Work Request Application Finished Thread alive User Mode Worker Mode Thread daemon 1 thread2 threads5 threads

15. Server Architecture Workers incoming requestsUsers incoming requests Http Server Database Applications Tasks Results Accounting Dispatcher Scheduler Communication Layer XML-RPC TCP SSL tasks host

16. Application integration l Registering application. l Providing binaries for different runtime (OS and CPU). –Application execution grain. –parameters and results size. l and why not, a submission interface.

17. Implementation /technologies Data Base MySQL PerlDBI Java JDBC Server Java JNI Communication protocol XML-RPC SSL Http Server PHP3-4 Installation GNU autotool User Interface Perl OO Gtk-Perl Pre requisite for installation: database (Mysql), web server (apache), PHP, JAVA virtual machine.

18. Status and Future Works l First version (Beta) –Free License (GPL) –code on cvs repository, code stabilization. l Future work. Benchmarking and monitoring. Lightweight worker for mobile device. Inter worker communication. l Collaboration –Electrical and Computer Engineering Department of Toronto University. –Wuhan University (China).

19. Conclusion l Objective: –a platform for experimenting on global computing issues. l Architecture design –high performance –scalability and fault tolerance –large number of users (Personal Computer & Personal Devices) l Auger Observatory l MyXtremWeb Program –Collaborators set up their own Global Application. www.XtremWeb.net