Institute for Visualization and Perception Research 1 © Copyright 1999 Haim Levkowitz Java-based mobile agents

Institute for Visualization and Perception Research 2 © Copyright 1999 Haim Levkowitz Java effective for mobile agents in e-commerce

Institute for Visualization and Perception Research 3 © Copyright 1999 Haim Levkowitz Earlier technologies “Fathered” mobile agents Dev’d to improve RPC for distributed programming Process migration Remote evaluation Mobile objects

Institute for Visualization and Perception Research 4 © Copyright 1999 Haim Levkowitz Process migration Move entire address space among computers Reduce net BW compared to RPC Multiple RPCs to execute app ==> Entire process can migrate No way to return data back to source node wo entire process returning

Institute for Visualization and Perception Research 5 © Copyright 1999 Haim Levkowitz Remote evaluation Send request in form of program (not entire process address space) Remote executes + returns results No need to transmit process control data Lack ability to encapsulate more state info into program

Institute for Visualization and Perception Research 6 © Copyright 1999 Haim Levkowitz Mobile objects Extend remote eval Capture more program behavior within mobile object Objects migrate, carrying executable code, data (object specific properties), other objects Mobile agents improved …

Institute for Visualization and Perception Research 7 © Copyright 1999 Haim Levkowitz Mobile agents improved Reduce net traffic for app’s processing large quantities of data Earlier: client/server Ship data to program source Agents: ship program to data Also, autonomy: decide dynamically, where, when to travel

Institute for Visualization and Perception Research 8 © Copyright 1999 Haim Levkowitz Client/server vs. agent computing models ClientServer Network Interaction ClientServer Network Interaction Agent

Institute for Visualization and Perception Research 9 © Copyright 1999 Haim Levkowitz Mobile agents improvements (cont.) Adapt to changes in program state + net environment Asynchrounous interaction User can disconnect from net Store-and-forward mechanism Async + autonom ==> protect mission- critical app’s form unreliable net’s

Institute for Visualization and Perception Research 10 © Copyright 1999 Haim Levkowitz Mobile agent advantages (cont.) Traveling user Connect/disconnect Fault tolerance Security

Institute for Visualization and Perception Research 11 © Copyright 1999 Haim Levkowitz Java as a language for mobile agent dev Concordia Odyssey Voyager

Institute for Visualization and Perception Research 12 © Copyright 1999 Haim Levkowitz Java for mobile agents Multiplatform support “Write once, run anywhere” Ubiquity of JVM ==> Facilitate dissemination

Institute for Visualization and Perception Research 13 © Copyright 1999 Haim Levkowitz Java unique features Object serialization ==> Convert agent + state -->suitable form for net transmission Remote sys reconstruct

Institute for Visualization and Perception Research 14 © Copyright 1999 Haim Levkowitz Java unique features (cont.) Persistent agent state info Serialize agent’s state Write to persistent storage Retrieve state + use to reconstruct agent

Institute for Visualization and Perception Research 15 © Copyright 1999 Haim Levkowitz Java unique features (cont.) Network support Sockets URL comm. Distributed object protocol RMI: Remote method invocation Prog. Access to dist. object simple RMI handled by local proxy

Institute for Visualization and Perception Research 16 © Copyright 1999 Haim Levkowitz Java unique features (cont.) Class loading mechanism ==> Facilitate migration of code + state Dynamically load classes Classpath / net Code subject to security restrictions Fine-grain, configurable security policies Tight integration with Web...

Institute for Visualization and Perception Research 17 © Copyright 1999 Haim Levkowitz Tight integration with Web Applets can launch mobile agents Receive returning agents when done Servlets: function like CGI script May launch + receive mobile agents JNDI: Java Naming & Directory Interface ==> seamless connectivity via unified access to multi naming + directory services

Institute for Visualization and Perception Research 18 © Copyright 1999 Haim Levkowitz Generic mobile agent architecture Security Manager Generic Mobile Agent Server Generic Mobile Agent Server Interagent Communication Manager Application Gateway Directory Manager Agent Reliability Manager Agent Manager Network External Application Generic Mobile Agent Server

Institute for Visualization and Perception Research 19 © Copyright 1999 Haim Levkowitz Generic mobile agent architecture Six major components Agent manager Interagent communications manager Security manager Reliability manager Application gateway Directory manager

Institute for Visualization and Perception Research 20 © Copyright 1999 Haim Levkowitz Agent manager Send agents to remote hosts Receive agents for execution on local host Serialize agent prior to transport Pass serialized form to counterpart on destination Really to reliability manager Ensure reception on other side

Institute for Visualization and Perception Research 21 © Copyright 1999 Haim Levkowitz Agent manager Upon reception Reconstruct Agent + objects ref’d Create execution context

Institute for Visualization and Perception Research 22 © Copyright 1999 Haim Levkowitz Mobile agent system (JVM) Auto invoke security manager Authorize any op’s using sys resources Request agent manager to transport agent to correct location

Institute for Visualization and Perception Research 23 © Copyright 1999 Haim Levkowitz Security manager Protect host + mobile agents against unauthorized code Authenticate received agent Encrypt agents before Transmission Saving to storage Digitally sign agents Exchange certificates

Institute for Visualization and Perception Research 24 © Copyright 1999 Haim Levkowitz Reliability manager Ensure robustness of mobile agent system Shield agents from server / sys crash Guarantee persistence of State associated with agents Mobile agent sys Use transactional queuing to ensure agents reach destination even during sys crashes

Institute for Visualization and Perception Research 25 © Copyright 1999 Haim Levkowitz Interagent communications manager

Institute for Visualization and Perception Research 26 © Copyright 1999 Haim Levkowitz Application gateway

Institute for Visualization and Perception Research 27 © Copyright 1999 Haim Levkowitz Directory manager

Institute for Visualization and Perception Research 28 © Copyright 1999 Haim Levkowitz Find me a ski vacation

Institute for Visualization and Perception Research 29 © Copyright 1999 Haim Levkowitz A killer opp

Institute for Visualization and Perception Research 30 © Copyright 1999 Haim Levkowitz What’s next?