DS-Grid: Large Scale Distributed Simulation on the Grid

1. DS-Grid: Large Scale Distributed Simulation on the Grid Stephen John Turner, Wentong Cai Parallel & Distributed Computing Centre Nanyang Technological University, Singapore Georgios Theodoropoulos Midlands e-Science Centre University of Birmingham, UK Brian Logan University of Nottingham, UK

2. Outline • MeSC and the DS-Grid Project • Motivation & Challenges • HLA_Grid • Benchmark Experiments • HLA_Grid_RePast • Large Scale Agent Based Simulation • Experiments and Results • Conclusions and Future Work e-Science Workshop 18.7.2006

3. MeSC: Centre of Excellence – Modelling and Simulation of Large Complex Systems • Funded by the UK e-Science programme • Part of the national Grid infrastructure of the UK • Virtual centre with a base in the School of Computer Science • www.mesc.bham.ac.uk e-Science Workshop 18.7.2006

4. The DS-Grid Project • One of only four “Sister Projects” funded by the e-Science Core Programme • UK-Singapore Grid link e-Science Workshop 18.7.2006

5. Motivation • The development of complex simulation applications usually requires collaborative effort from researchers with different domain knowledge and expertise, possibly at different locations • These simulation systems often require huge computing resources and the data sets required by the simulation may also be geographically distributed • The Grid offers an unrivalled opportunity: • Enables collaboration • Enables the use of distributed computing resources, • Allows access to geographically distributed data sets • Supports service-oriented architectures that can facilitate model and resource discovery e-Science Workshop 18.7.2006

6. DS-Grid Vision • A Grid “plug-and-play” distributed collaborative simulation environment, where researchers with different domain knowledge and expertise, at different locations, develop, modify, assemble and execute distributed simulation components over the Grid e-Science Workshop 18.7.2006

7. Federation SOM SOM SOM SOM SOM SOM SOM SOM FOM SOM HLA Rules (Federations) HLA Rules (Federates) SimulationSurrogates Passive Viewers Simulations Interface FED Run-Time Infrastructure (RTI) Federation Management Declaration Management Object Management Ownership Management Time Management Data Distribution Management High Level Architecture e-Science Workshop 18.7.2006

8. RTI RTI RTI Model Factory Model Factory RTI RTI federate federate federate federate federate HLA and the Grid • Discovery of Models • Discovery of Resources • Management of Simulation Execution e-Science Workshop 18.7.2006

9. Challenges • Model Discovery and Matching • While HLA provides interoperability at the communication level there is little support for interoperability at the semantic level • Resource Management • HLA does not provide support for resource management and dynamic load balancing • Simulation Management on the Grid • HLA does not provide any support for collaborative development of simulation components • New Grid-aware collaborative environments for distributed simulation must be developed e-Science Workshop 18.7.2006

10. HLA_Grid Grid Services: indexing, discovery, resource management, monitoring services … Grid Services Globus Proxy Simulation Code Proxies & Federates Grid-aware HLA API HLA API Grid-aware HLA API HLA API Globus RTI on LAN Globus Grid Network Client Resource e-Science Workshop 18.7.2006

11. Experimental Environment e-Science Workshop 18.7.2006

12. Benchmark Experiments • Overhead in cluster: latency = 50 millisecond • Use of GT3, encoding/decoding of parameters/results, and the communication costs • Overhead in WAN: latency = 1150 millisecond • Mainly caused by the increase in communication using SOAP messages over long distances -> increase number of packets e-Science Workshop 18.7.2006

13. HLA_Grid_RePast • Executes distributed, large scale simulations of agent-based systems over the Grid • Integrates HLA_Grid and RePast (Java based toolkit for lightweight agents) • Each federate divided into two parts: • Client Side • RePast Code and HLA_Grid Library • Remote Side • Proxy RTI Ambassador and Federate Proxy Ambassador e-Science Workshop 18.7.2006

14. Structure of HLA_Grid_Repast e-Science Workshop 18.7.2006

15. Case Study: Tileworld e-Science Workshop 18.7.2006

16. Network Configuration for Experiments e-Science Workshop 18.7.2006

17. Experimental ResultsPerformance on a LAN (PC Cluster) with one agent federate e-Science Workshop 18.7.2006

18. Experimental ResultsPerformance on a WAN (Grid) with one agent federate e-Science Workshop 18.7.2006

19. Conclusions • Advantages • Avoids many firewall issues as client communicates with proxy via Grid services • Enables easier integration with non HLA simulators • Hierarchical federations may be constructed easily • Provides easy migration of client code as proxy does not need to be migrated • Disadvantages • Overhead of communication as all simulation events use Grid services e-Science Workshop 18.7.2006

20. Future Work • Further analysis of communication network traffic • Additional Case Studies • Grid “plug-and-play” Environment based on Service-Oriented Architecture • Component Based Simulation Development • Service Discovery • Semantic Matching • Efficient Execution • Resource Management • Collaborative Environment for Distributed Simulation • Workflow Management e-Science Workshop 18.7.2006