Design and Implementation of Runtime Reflection in Communication Middleware: the dynamicTAO Case Manuel Román, Fabio Kon, Roy H. Campbell University of Illinois at Urbana-Champaign

Index zIntroduction zdynamicTAO yArchitecture yDynamic Configuration yORB Consistency ySecurity and Safety zConclusion

Introduction zExecution environments are subject to frequent changes zApplications have knowledge to adapt to changes but cannot use it zDynamic reconfiguration not offered by most communication middleware systems

zdynamicTAO uses reflection techniques to allow runtime modifications zThe adaptation work is pushed to the middleware layer Introduction

dynamicTAO Introduction  dynamicTAO Architecture Dynamic Configuration ORB Consistency Security and Safety Conclusion

zBased on TAO, developed at the Washington University in Saint Louis zAllows on-the-fly reconfiguration while keeping the ORB engine consistent dynamicTAO

dynamicTAO Architecture zdynamicTAO is based on a key entity: Component Configurator Domain Configurator TAOConfigurator Servant1 Configurator Concurrency StrategyScheduling Strategy Connection Strategy

dynamicTAO Architecture Local File System Persistent RepositoryACE_Service_RepositoryACE_Service_Config Dynamic Service Config Domain Configurator Servant Configurator TAO_Configurator Network Broker

dynamicTAO Introduction  dynamicTAO Architecture  Dynamic Configuration ORB Consistency Security and Safety Conclusion

zThree interfaces exported by the Dynamic Service Config: yCORBA interface yTCP/IP interface ySmart Packets zAll three implement the Dynamic Configuration Protocol dynamicTAO Dynamic Configuration

zCommands offered by the Dynamic Configuration Protocol: List Loaded ImplementationsList Domain Components List CategoriesList Hooks List ImplementationsLoad implementation Get UsageHook Implementation Get Implementation InfoRemove Implementation Get Component InfoConfigure Implementation Get Hooked ComponentUpload Implementation Delete ImplementationSuspend Implementation Resume ImplementationAdd / Remove Hook dynamicTAO Dynamic Configuration

dynamicTAO Introduction  dynamicTAO Architecture  Dynamic Configuration  ORB Consistency Security and Safety Conclusion

zdynamicTAO is kept consistent while dynamic changes are carried out. zIssues associated to implementation switching: yChecking compatibility with remaining impl. yTransferring state from the old implementation yImpact on current client requests dynamicTAO ORB Consistency

zIssues associated to implementation deletion: yGarbage collection yVersion control dynamicTAO ORB Consistency

dynamicTAO Introduction  dynamicTAO Architecture  Dynamic Configuration  ORB Consistency  Security and Safety Conclusion

dynamicTAO Security and Safety zSecurity refers to the mechanisms that control who can modify the ORB yCORBA security service yCherubim project and active capabilities zSafety prevents crashing the ORB due to faulty implementations: yJava Sandbox

Conclusion Introduction  dynamicTAO Architecture  Dynamic Configuration  ORB Consistency  Security and Safety  Conclusion

zChanges will happen. Adaptation is required. zdynamicTAO provides the tools to safely introduce those changes zIncoming era of ubiquitous computing requires a highly dynamic customizable framework dynamicTAO Conclusion