1. Emulation in Data Grid eXplorer

2. Emulation problematic Distributed applicationTarget environment Simulation Emulation App. Model Env. model Formal analysis Model checking Proof Simulation tools Env. « hardware » model Real « controlled » execution

3. Emulation loop Phase 1 : Configuration Phase 2 : Experimentation Measurements / Trace collect Phase 3 : Comparison with real trace Phase 4 : Extrapolation Tuning

4. 2 types of emulation distance (latency, bandwidth, failure rate …)  dummynet based solution  Difficulty : high number of configurations (High speed network, VTHD, Internet) Number of nodes  Partitioning resources of a node  Difficulty: side effect

5. Related works Modelnet Network emulation / node virtualization Emulab Network emulation / nodes simulation PlanetLab Large scale distributed architecture (1000 nodes) Real condition Reproductability ?

6. Modelnet Http://issg.cs.duke.edu/modelnet.html Router / Dummynet Virtualisation N noeuds => M noeuds N>>M

7. Netbed (Emulab) Similar to « Modelnet » Topology description => NS script Use of Dummynet Tools for mapping logical route => physical configuration NS simulateur to emulate several host in a node http://www.emulab.net/ 3 Sites

8. (Intel Research) An open testbed for developing, deploying, and accessing planetary-scale services. http://www.planet-lab.org/

9. Experiences related to emulation in Data GDX System VGRID (LRI / INRIA) Simulation / Emulation (IMAG-ID) Heterogenity (Loria) Schedulling (LIFL / LRI) Data storage and data sharing (IRISA/ENS-Lyon/LIP6) Fault tolerance (LIP6 / INRIA / LRI) Security (LRI / Supélec) Cellular distributed system (LORIA/Supelec) Communication in P2P (LIFL) Network Internet emulation (LAAS - LIP6) Ingeneery (LRI) Multicast (LIP) Internet new generation

10. Program of the emulation sessions Grid Data Service - Gabriel Antoniu (IRISA) Scheduling Strategy for Large Scale Distributed Systems: Serge Petiton (LILF, Inria Grand-Large) A simulation tool for large scale nearest neighbor scheduling: Thomas Herault (LRI, Inria Grand-Large) Experience with Dummynet, A. Jebali (Inria Regal)