Resource-based Approach to Feature Interaction in Adaptive Software

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Resource-based Approach to Feature Interaction in
Adaptive Software
Betty H.C. Cheng Software Engineering and Network
Systems Laboratory Michigan State
University http//www.cse.msu.edu/SENS Authors
Jesús Bisbal and Betty H.C. Cheng
jesus.bisbal_at_upf.edu, chengb_at_cse.msu.edu
ACKNOWLEDGEMENTS This work has been supported in
part by grants NSF EIA-0000433,
CDA-9700732,EIA-0203060, EIA-0130724,
ITR-0313142, Department of the Navy, and Office
of Naval Research under Grant No.
N00014-01-1-0744.
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Context

• Aspects of self-management problem being
  addressed?
• Self-management involves dynamic adaptation
• Focus on assurance issues of self-management
• Feature interaction
• What aspects are you NOT dealing with?
• Adaptation mechanisms
• ADLs for self-management/adaptation
• Programming Languages
• Domains, properties, or applications targeting?
• Mobile computing applications
• Component-based software development
• Assurance issues

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RAPIDware Project

• Ongoing project in SENS Laboratory
• Funded by U.S Office of Naval Research
• Critical Infrastructure Protection /Adaptable SW
  Program
• Goal Software (middleware) that can protect
  itself from
• Hardware and software component failures
• Changing environmental conditions
• Changing requirements (e.g. security policies)
• Malicious entities
• Applications
• Dynamic power management
• Dynamic error correction for data
  transmission/receipt
• Dynamically changing security algorithms and
  policies
• Dynamic introduction of fault-tolerant
  capabilities

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Example RAPIDware Activities

• Transparent shaping
• Automated weaving adaptive behavior into existing
  programs WOSS02,ICAC04,DOA04,ICDCS04
• Rigorous software engineering of adaptive code
• Safe adaptation using dependency analysis
  WADS04
• Synthesis of fault-tolerant code from
  specifications DSN04
• Adaptive overlay networks ICNP03, ICDCS04
• Middleware-kernel interaction MPAC04
• Decision-making software using machine learning
  techniques ICDL04
• Adaptive energy management IWQoS04

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Outline

• Adaptive software components
• Feature interactions
• Resource-based approach
• Implementation wireless image retrieval scenario
• Future work

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Adaptive Software Components

• Dynamically adapt at run-time
• Reactive to environmental or user requirement
  changes
• Adaptive mechanisms actively investigated
• Assurance of adaptation mechanisms somewhat
  neglected to date

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Feature Interactions

• Widely investigated by the telecommunications
  industry
• Receiving increasing attention from other
  domains
• Whenever several software entities control a
  shared resource
• A feature interaction occurs when the behavior
  of one feature is affected by the behavior of
  another feature, or another instance of the same
  feature L. Blair et al., 2001
• Ex electronic mail, web services,
  component-based software

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Feature Interactions

• Off-line (design-time) approaches
• Formally describe each feature (e.g. FOPL, CTL)
• Reason about interactions (e.g. theorem provers,
  model checking)
• Requires a priori knowledge of complete set of
  features
• On-line approaches (run-time) approaches
• Features Manager mediates between features to
  avoid interactions
• Requires training phase or domain-specific
  knowledge

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RAFTING Resource-based Approach to FeaTure
InteractioN

• Premise
• For practical purposes all feature interactions
  are or can be thought as being caused by resource
  contention
• Shifts focus from features to resources used by
  those features
• Simplifies feature interaction detection process
• Well-suited to component-based software
  development using third-party vendor COTS
• Vendors do not disclose internal workings of
  components, only externally observable behavior

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Resource-based Approach to Feature Interaction

• Features are seen as information transformation
  processes (i.e., services)
• Resources are the required inputs and outputs

Resource1
Output1
Resource2
Feature
Output2
Resource3
...
Outputm
...
Resourcen
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Resource-based Approach to Feature Interaction

• Goals are the requirements of the overall
  behavior obtained by composing a set of features

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Resource-based Approach to Feature Interaction

• Feature-Resource Relationships defined in terms
  of usage and production of a resource
• USES()
• Describes how a feature uses a given resource or
  perform its task
• PRODUCES()
• Indicates that a feature produces a resource
• Resources can be rather abstract
• E.g. time could be considered a resource in
  order to describe time-dependent relationships

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Resource-based Approach to Feature Interaction

• System specifications
• Features
• Resources
• Relationships
• Goals
• General objective
• a generic features manager will only require this
  information in order to mediate between features

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Wireless Image Retrieval Scenario

• Setup
• Producer/consumer architecture
• Producer(s) run on mobile devices and
  transmit information over a wireless link
• E.g. iPAQs, wearables, and other handhelds
• Consumer runs on a more powerful device (desktop)
  and processes information

• Dynamic Adaptation Scenario
• Limited resources of producers requires dynamic
  adaptation to fulfill quality of service (QoS)
  goals
• Insertion/Removal of Forward Error Correction
  (FEC) filter to improve quality of communication
  link
• Modification of Image Resolution to reduce
  battery consumption, when possible

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Wireless Image Retrieval Scenario

• Producer application
• Device equipped with camera

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Wireless Image Retrieval Scenario

• Consumer application (e.g., headquarters)
• Receives informationtransmitted from several
  producers

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Future Work

• Can all interesting interactions be modeled using
  this resource-centric approach?
• If not, which ones can?
• Resolution policies expressed in terms of
  resources (for uniformity) or in terms of
  features (users perspective)

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Happy Halloween!
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Questions?