1. 09/03/2003Parrallel Computing Conference 20031 JToe : a Java API for Object Exchange Serge Chaumette, Pascal Grange, Benoit Métrot, Pierre Vignéras LaBRI, UMR CNRS 5800 Université Bordeaux 1 FRANCE

2. 09/03/2003Parrallel Computing Conference 20032 Copyright Java and all Java-based marks are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. The authors are independent of Sun Microsystems, Inc.

3. 09/03/2003Parrallel Computing Conference 20033 Our Research Activities Distributed Systems Client/server PDAs Java Card RMI CORBA Mobiles, wireless Object oriented technologies

4. 09/03/2003Parrallel Computing Conference 20034 Our Research Activities Our aim is to contribute to support users of such platforms based on our experience of distributed systems and embedded/mobile technologies Four main actions Automatic distribution of multi-threaded Java codes Distributed execution run-time Formal and practical validation Embedded and wireless Java, smart cards, nomadic

5. 09/03/2003Parrallel Computing Conference 20035 JToe What it is API for object transport in Java Dedicated to the exchange of objects Clearly specifies the notion of object exchange Allows any optimized implementation What it is not A RMI like framework No distributed garbage collector No remote method invocation No registery management

6. 09/03/2003Parrallel Computing Conference 20036 Outline Why to create a new API ? The JToe API and its implementations Performance measurements Perspectives

7. 09/03/2003Parrallel Computing Conference 20037 Outline Why to create a new API ? The JToe API and its implementations Performance measurements Perspectives

8. 09/03/2003Parrallel Computing Conference 20038 Distributed object computing A good framework in general : RMI RMI allows object exchange Object exchange relies on serialization Unefficiency of serialization  Unefficiency of RMI

9. 09/03/2003Parrallel Computing Conference 20039 The serialization process Generic encoding process Too general to achieve high performance 1011011101110 object object Serialization Deserialization ObjectOutputStream ObjectInputStream Network HDD

10. 09/03/2003Parrallel Computing Conference 200310 Possible strategies (1/2) Inheriting Object(Output/Input)Stream Pros Legacy code reuse Optimisation for homogeneous cluster Cons Stream oriented Cumbersome with non-stream based transport layer

11. 09/03/2003Parrallel Computing Conference 200311 Possible strategies (2/2) Re-implementing RMI Pros Allows every type of serialization optimisation Optimization for homogeneous clusters Non stream oriented Cons Distributed garbage collector Remote method invocation Threads management Registery management

12. 09/03/2003Parrallel Computing Conference 200312 Outline Why to create a new API ? The JToe API and its implementations Performance measurements Perspectives

13. 09/03/2003Parrallel Computing Conference 200313 Features Simple API Dedicated to object exchange One sided communications Allows every type of optimisation Optimisation for homogeneous clusters Non stream oriented

14. 09/03/2003Parrallel Computing Conference 200314 The JToe API public interface Node { void copy(Serializable object) throws JToeException; } public interface CopyListener { void copied(Serializable object); }

15. 09/03/2003Parrallel Computing Conference 200315 Current JToe implementations 100% Java implementations (RMI and TCP) Object exchange is performed using Java serialization Used as reference implementations for regression tests Jtoe applications are 100% Java Applications JVM level implementation Tranfer of raw memory areas Relies on Jikes RVM

16. 09/03/2003Parrallel Computing Conference 200316 JikesRVM Developped by IBM Open Source Written in Java Pointers can be handled from Java code Good experimentation tool

17. 09/03/2003Parrallel Computing Conference 200317 1 – Allocate in nursery JToe for JikesRVM (an overview) Nursery 3 - Rebuild pointers 2 - Read data Garbage Collector 4 – Memory areas become Java Object Java Reference

18. 09/03/2003Parrallel Computing Conference 200318 Outline Why to create a new API ? The JToe API and its implementations Performance measurements Perspectives

19. 09/03/2003Parrallel Computing Conference 200319 Test platform Ping pong tests between two computers Linux 2.4.18 Intel 1.7Ghz computers with 512Mo RAM JDK 1.4.1

20. 09/03/2003Parrallel Computing Conference 200320 Arrays of integers

21. 09/03/2003Parrallel Computing Conference 200321 Arrays of doubles

22. 09/03/2003Parrallel Computing Conference 200322 Vectors

23. 09/03/2003Parrallel Computing Conference 200323 TreeSets

24. 09/03/2003Parrallel Computing Conference 200324 Summary Why to create a new API ? The JToe API and its implementations Performance measurements Perspectives

25. 09/03/2003Parrallel Computing Conference 200325 Perspectives JToe for JikesRVM will have an enhanced graph exploration algorithm LAPI and Myrinet versions are planned Reimplementation of RMI over JToe A JToe optimised implementation for SUN and IBM Java Virtual Machine