INTELLIGENT AGENTS AND BIST/BISR - WORKING TOGETHER IN DISTRIBUTED SYSTEMS

INTELLIGENT AGENTS AND BIST/BISR - WORKING TOGETHER IN DISTRIBUTED SYSTEMS Alfredo Benso1, Liviu Miclea2, Enyedi Szilárd2 1 Politecnico di Torino (Italy)2 Technical University of Cluj-Napoca (Romania) 2002 International Test Conference 05/20/02 V5.2

Purpose • To reduce the complexity in testing large, heterogeneous computer-based distributed systems • To enable “Plug and Play” testing of new devices added to the system • To present the real challenges and potential benefits of an agent-based approach

Plan of Presentation • Present the problem • Introduce software agents • Place agents in context • Present a simulation environment • Summarize some possible future activities

The problem • We call heterogeneouscomputer-baseddistributed system a network of independent computer systems that appear to the users as a single system (e.g., a hospital computer network)

The problem • How can I implement, manage, and organize the test of a heterogeneous computer-based distributed systems?

Testing heterogeneous distributed systemsState of the art • DBIST [Miclea et al. ETW’00]: centralized control authority to start/stop BIST procedures • HD2BIST [Benso et al. ITC’00]: a distributed hierarchical test infrastructure to test SoC devices • IEEE 1232 standards: common exchange formats for reasoning systems used in system test and diagnosis

What is a software Agent • Carl Hewitt (1997) • “a self-contained, interactive and concurrently-executing object, with some encapsulated internal state and which could respond to messages from other similar objects” • a software component which is capable of acting exactingly in order to accomplish tasks on behalf of its user

Are able to work unaided Don’t constantly need instructions Proactive Share information with each other Able to agree on subtasks Improve their actions with experience Cooperate Learn Software Agents

Agent Applications • workflow management • network management • air-traffic control • smart databases • command and control • education • data mining • electronic commerce • ......

Agents testing distributed systems • The basic idea of this research is to define an agent society whose goal is to test the hardware components of a heterogeneous computer-based distributed system • Agents must be able to define a test plan for a new hardware by gathering test patterns, algorithms, repair functions, etc..., from the society itself.

Why Agents? • Benefits: • Modularity, which reduces complexity • Speed, due to parallelism • Flexibility, new tasks are composed more easily from the more modular organization

The Agents’ duties • The goal of the Agent society is to detect, diagnose, and repair faults; • For each step, they have to: • get the necessary information to make and execute a plan • execute the plan • analyze the results (not compulsory)

Utility Agents NameServer Facilitator Visualizer Device 1 Device 2 Device 3 Field Agent Field Agent Field Agent Agent society

Device 1 Field Agent Field Agents • Emphasize autonomy and cooperation with other agents; • Typically operate in open and time-constrained multi-agent environments; • High learning capabilities; • Software processes; • They analyze the sub-systems and organize a test plan; • They are also able to test/repair some types of devices

Utility Agents NameServer Facilitator Visualizer Utility Agents: NameServer • They have the anagraphical information about the society; • They provide the FAs with other Agents’ address; • Their job is similar to the DNS internet servers; • There is at least one NameServer Agent in the society.

Utility Agents NameServer Facilitator Visualizer Utility Agents: Facilitator • They have the topological information about the knowledge distributed in the society; • They are the Yellow Pages of the society; • It also inquires the FAs to know about their new skills and resources; • They also keep a list of “demanded” abilities.

Utility Agents NameServer Facilitator Visualizer Utility Agents: Visualizer • They have the ability to show the system test status; • Using the Visualizers, the user can monitor the Agents’ activity from anywhere in the system.

Field Agent CPU RAM Example Field Agent: • Prepare a test plan: • Get the system’s information: RAM type and size, CPU model, HD type, custom ASIC test mechanism, etc... • Look for the tests algorithms and procedures for each device Device n

Field Agent CPU RAM Example • The FA may or may not know how to test a device; • If it doesn’t know: • it asks the Utility Agents for other Field Agents able to solve the task; • It contacts the other FA and either learns the test procedure, or have the other Agent test the system; • If it detects a fault, it starts preparing a repair plan. Device n

Field Agent CPU RAM Example Utility Agents: • Respond to the Field Agents requests by supplying location of other Field Agents, or, if possible, directly test procedures and methods; Device n Utility Agents NameServer Facilitator Visualizer

The ZEUS Tool-Kit

Agents’ society simulation • We used ZEUS to validate the feasibility of the idea; • We implemented a society with: • Utility Agents; • Field Agents able to test, repair, and inject faults.

Future work • Standardize Agents’ capabilities, communication protocols, and interactions; • Implement an Agent society on a LAN; • Design and implement an Agent society on a mobile phone network.

Conclusions • We proposed an Agents society able to test new devices plugged in the system; • Utility and Field Agents can do the task of many high-level server administrators and, at the same time: • Reduce costs • Reduce test and repair time • Maximize the reuse of the test procedures of different devices

Thank you Any Questions?

INTELLIGENT AGENTS AND BIST/BISR - WORKING TOGETHER IN DISTRIBUTED SYSTEMS