CEN-4015, Software Project, Spring 2006

Transparent Shaping Transparent Shaping of Existing Software to Support of Existing Software to Support

Pervasive and Autonomic ComputingPervasive and Autonomic Computing

S. Masoud Sadjadi

Autonomic Computing Research Laboratory (ACRL)School of Computing and Information Sciences

Florida International University

Email: sadjadi@cs.fiu.eduURL: http://www.cs.fiu.edu/~sadjadi/

2CEN-4015, Software Project, Spring 2006.

Demand for Pervasive Computing – Promises anywhere, anytime access to data and computing.

Examples

Need for dynamic adaptation– Heterogeneity of hardware, network, software– Dynamics of the environmental conditions– Limited resources (CPU, memory, battery, etc.)

Pervasive Comp.

Why Dynamic Adaptation?Why Dynamic Adaptation?OvervieOverview:w:Motivation

Autonomic Comp.

Wearable Computing Military ApplicationsTRAP.NET

Language-Based

Approach

3CEN-4015, Software Project, Spring 2006.

Demand for Autonomic Computing– Promises self-management in complex and critical systems.

Examples:

Pervasive Comp.

Why Dynamic Adaptation?Why Dynamic Adaptation?

Need for dynamic adaptation– hardware component failures– network outages– software faults– security attacks

Autonomic Comp.

OvervieOverview:w:Motivation

Financial Networks Water/Power SystemsTRAP.NET

Language-Based

Approach

4CEN-4015, Software Project, Spring 2006.

Adaptable ProgramsAdaptable Programs Definition

– An adaptable program is a program whose behavior can be changed (adapted) dynamically (at run time).

Problem– Developing and maintaining adaptable programs are

nontrivial tasks.

Challenges– New adaptable programs

Adaptive code is scattered over functional code. Unanticipated and transient adaptations.

– Enhancing existing programs Source code may not be available. It may not be desirable to modify the source code.

Adapt. Programs

OvervieOverview:w:Motivation

Trans. Shaping

Dynamic Adapt.

Approach

Realizations

TRAP.NET

Language-Based

5CEN-4015, Software Project, Spring 2006.

Transparent ShapingTransparent Shaping Definition

– A new programming model that supports dynamic adaptation in existing programs without the need to modify their source code directly.

Key technologies

Aspect-Oriented Programming

Behavioral Reflection

Component-Based Design

Middleware

Transparent ShapingTransparent Shaping

Trans. Shaping

Adapt. Programs

Dynamic Adapt.

OvervieOverview:w:Motivation

Realizations

Approach

TRAP.NET

Language-Based

6CEN-4015, Software Project, Spring 2006.

Dynamic AdaptationDynamic Adaptation

Dynamic adapt.

Adapt. Programs

Trans. Shaping

OvervieOverview:w:Motivation

Realizations

X4X3

X8

Second Step:at run time

X5 X7X6

X9S1 S2

Dynamic adaptation in two steps

X1

(adapt-ready program)

First Step:at compile, startup, or load time

X2

(adapt-ready program)

X0

(existing program)

X working program reversible design decisiondesign decision subfamily boundary

Dynamic adaptation in two steps1. An adapt-ready program is produced statically

The existing program with generic interceptors, called hooks, at certain points in its execution path.

Dynamic adaptation in two steps1. An adapt-ready program is produced statically

The existing program with generic interceptors, called hooks, at certain points in its execution path.

2. Adaptable programs are produced dynamically Using the hooks, a composer can convert the adapt-

ready program into a more appropriate adaptable program by inserting and removing new adaptive code.

Approach

TRAP.NET

Language-Based

7CEN-4015, Software Project, Spring 2006.

Transparent Shaping RealizationsTransparent Shaping Realizations Transparent shaping targets distributed applications. Depending on where the hooks are incorporated inside

an existing program during the first step of the shaping process, we identify three approaches to transparent shaping.1. inside an application program itself2. inside its supporting middleware3. inside the system platform.

Client Program Server Program

ApplicationLayer

MiddlewareLayer

Program component Flow of service request Hook

process boundaries

NetworkNetwork

Requester Component

ProviderComponent

OperatingSystem

Interaction

A typical client/server application.

Adapt. Programs

Trans. Shaping

Dynamic Adapt.

OvervieOverview:w:Motivation

Realizations

Approach

Transparent shaping targets distributed applications. Depending on where the hooks are incorporated inside

an existing program during the first step of the shaping process, we identify three approaches to transparent shaping.1.1. inside an application program itselfinside an application program itself2. inside its supporting middleware3. inside the system platform.

TRAP

TRAP.NET

Language-Based

8CEN-4015, Software Project, Spring 2006.

TRAPTRAP

Transparent Reflective Aspect Programming (TRAP) is an instance of transparent shaping – Supports dynamic adaptation in OO programs– Does not require direct modifications to source

code

A two-step approach to dynamic adaptation – The developer can select, at compile time, a subset

of classes in the existing program to be reflective at run time.

– The objects of such reflective classes can be adapted at run time.

TRAP/J

Case Study

TRAP

Summary

Language-Based

OvervieOverview:w:Motivation

Approach

TRAP.NET

9CEN-4015, Software Project, Spring 2006.

TRAP/J Operation at Compile TimeTRAP/J Operation at Compile Time

TRAP

Case Study

TRAP/J

Existing program

Selecting classes

Generating hooks

Weaving hooks

Existing program

Selecting classes

Generating hooks

Weaving hooks

Existing program

Selecting classes

Generating hooks

Weaving hooks

Existing program

Selecting classes

Generating hooks

Weaving hooksSummary

A configuration file (contains a list of classes to become reflective)

Original Application(.class files)

AspectJ Compiler (ajc)

Generated adapt-ready application (.class files)

Data Flow A File A Process TRAP/J Boundary

MetaLevelClass

BaseLevelClassAspect

MetaLevelClass

BaseLevelClassAspect

Wrapper-Level Class

Meta-Level Class

Intercepting Aspects

Intercepting Aspect Generator Reflective Class Generator

TRAP/J at Compile Time

Language-Based

OvervieOverview:w:Motivation

Approach

TRAP.NET

14CEN-4015, Software Project, Spring 2006.

Contact InformationContact Information

Questions?Thank you!

S. Masoud SadjadiAssistant Professor of Computer Science University Park, ECS 212C11200 S.W. 8th StreetMiami, FL 33199

Email: sadjadi@cs.fiu.eduURL: http://www.cs.fiu.edu/~sadjadi/

RAPIDware Project: http://www.cse.msu.edu/rapidware/SENS Laboratory: http://www.cse.msu.edu/sens/

OvervieOverview:w:Motivation

Language-Based

Approach

TRAP.NET