A Conflict Resolution Control Architecture for Self-Adaptive - - PowerPoint PPT Presentation

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 1

A Conflict Resolution Control Architecture for Self-Adaptive Software

• Prof. A. Taleb-Bendiab

School of Computing and Mathematical Sciences Liverpool John Moores University {cmsnbadr, d.reilly, a.talebbendiab}@livjm.ac.uk http://www.cms.livjm.ac.uk/except

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 2

Dependable software

• Autonomic computing: a recent trend

– Devolving software management, maintenance to software

• Self-organising, self-healing, sentient, self-adaptive, self-aware, etc.

– Requiring meta-systems and meta-reasoning to;

• Continuous measurement and/or reflection on operational systems
• High-assurance: high-{integrity, availability, etc.}

– Complexity and uncertainty hiding through;

• adaptive capability to respond to changes including: fault&intrusion-

tolerance, thus masking errors, failures, etc.

• Dynamic architecture transformation and reconfiguration strategy;

– This requires reasoning and consideration of a set of concerns; » software architecture model including; components and their interactions, the properties and policies, » Style and composition rules and/or norms that limit the allowable systems adaptation operations.

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 3

Integrity Management

• Dynamic architecture transformation often lead to

inconsistencies and conflicts

– Systems integrity – Quality of service, etc.

• Requirement for a software adaptation engine with;

– Conflict detection and identification – Conflict resolution

• Solution generation, negotiation
• Change plan enactment, etc.

– Control strategies defining;

• Transformation rules, regulations, patterns, etc.
• Our approach is a middleware to support for self-

adaptive software conflict management.

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 4

Related Work

• Self-Adaptive Software

– Can be defined as software with computational reasoning capabilities to monitor and change its

• wn structure and/or behaviour to adapt to its
• perating environment and recover from errors.
• Reflective middleware
• Dynamic configuration control and management
• Conflict resolution

– Negotiation Protocol – Exception handling

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 5

Key V = Variety

Environment

V

V

System

Management Unit

V

= Attenuation = Amplification

Reference Model #1

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 6

Reference Model #2

Desires

World Model

Deliberation Process

Intentions

Opportunity Analyser

Environmental Scan

Filtering Process Plans

Surviving

Plans

Intentions

Planning Process Plan Library Reasoner Internal Model

Internal Model

Status Resource Bargaining Process

Intentions Overall Plans

R e s

• u

r c e s

Accountability

Intentions

System Three System Four System Five

Operational Status

Scheduling

Overall Schedule

Local Plans Local Schedule Local Monitoring data Local Monitoring data

Local Monitoring data Overall Schedule Monitoring to next recursion

Monitoring data

Further possible managerial Activities

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 7

An Architectural Model

Application Development Support Applications Supporting Services Application Services

JINI SERVICES LOOKUP SERVICE JavaSpace REGISTRATION SERVICE MONITORING SERVICE CONFIGURATION SERVICE ASSEMBLING SERVICES OPERATIONAL SERVICE MANAGEMENT CONTROL MECHANISM BROKER COMMUNICATION SERVICE A1 A1 A1

C O M

B1 B2 B3 B4

C O M

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 8

Jini Lookup Service (LUS) Service Manager System Constraint Checker Conflicts Repair Strategies Exception handler Utility Remote Event Utility Service Manager Proxy Monitor Service Diagnose Service Boundary of Control mechanism Adaptation Strategies Client Proxy Client Service Proxy Service Services Supplier Remot e Event Reconfiguration Service Instrumentation Service Registration Service

Adaptation Usage Model

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 9

An Example: E-Fire Services

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 10

Example Programming Model

Service Manager Vehicle Operation Power Management Vehicle Recorder AVL Information Systems Database/ XML Servlet Incident Response WAP Cellular Walkie Talkie 3-in-1 Phone Management Service Reconfiguration Service Client 3 1 3 4 5 6 Monitor Service Manager Diagnose Adaptation Strategies Mgr1 Monitor Service Manager Diagnose Adaptation Strategies Mgr3 Monitor Service Manager Diagnose Adaptation Strategies Mgr2 Monitor Service Manager Diagnose Adaptation Strategies

Management Factory

Monitor Service Manager Diagnose Adaptation Strategies Mgr5 Monitor Service Manager Diagnose Adaptation Strategies Mgr4 r r r I r Instrumentation System 2 Mgr3

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 11

Demonstrator

Ad-hoc service assembly tool Architecture transformation tool Software instrumentation tool

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 12

Conclusions & Future Work

• Presented an architecture for conflict resolution and

management for

– Self-adaptive software – Supplied as a middleware service

• Presented an example illustrating;

– Propose programming model – Usage model

• Further work

– Resolution session control and management – Evaluation.

• A. Taleb-Bendiab, ICSE’02, Workshop on Architecture for Dependable Systems, Orlando, 20/09/99, Pages: 13

That’s the end – so I’m off !