A review of the rationale and architectures of PJama - a durable, flexible, evolvable and scalable orthogonally persistent programming platform

A primary goal of research into orthogonal persistence is to simplify significantly the construction, maintenance and operation of applications in order to save software costs, extend the range of applications and improve users’ experiences. To test such claims we need relevant experiments. To mount such experiments requires an industrial-strength persistent programming platform. The PJama project is an attempt to build such a platform and initiate those experiments. We report our design decisions and their consequences evaluated by four years of experience. We have reached a range of platforms, demonstrated orthogonality and provided durability, schema evolution with instance reformatting, platform migration and recovery. The application programming interface is now close to minimal, while we support open systems through a resumable-programming model. Our architecture is flexible and supports a range of optimisations. Performance measurements and current applications attest to our progress, but it is still possible to identify major research questions, and the experiments to test the utility of orthogonal persistence are still in their early stages. email address: [email protected] [email protected] © 2000 Sun Microsystems, Inc. All rights reserved. The SML Technical Report Series is published by Sun Microsystems Laboratories, of Sun Microsystems, Inc. Printed in U.S.A. Unlimited copying without fee is permitted provided that the copies are not made nor distributed for direct commercial advantage, and credit to the source is given. Otherwise, no part of this work covered by copyright hereon may be reproduced in any form or by any means graphic, electronic, or mechanical, including photocopying, recording, taping, or storage in an information retrieval system, without the prior written permission of the copyright owner. TRADEMARKS Sun, Sun Microsystems, Sun Ray, Solaris, Java, JavaBeans, JavaBlend, JDK, Enterprise Java Beans, Java Foundation Classes, Java RMI, Java Native Interface and PJava are trademarks or registered trademarks of Sun Microsystems in the United States of America and other countries. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. in the U.S. and other countries. Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems, Inc. For information regarding the SML Technical Report Series, contact Jeanie Treichel, Editor-in-Chief . A Review of the Rationale and Architectures of PJama: a Durable, Flexible, Evolvable and Scalable Orthogonally Persistent Programming Platform Malcolm Atkinson1 and Mick Jordan2