architectural models in a quality scenario-based analysis for self-adapting systems

7/29/2019 Architectural Models in a Quality Scenario-based Analysis for Self-Adapting Systems

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MENTA

Boris Rainiero Prez G.

Architectural Models in a Quality Scenario-

based Analysis for Self-Adapting Systems


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Table of Contents

Context

Problem

Proposal Experimentation & Validation

Working Agenda

Questions& Suggestions


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Table of Contents

Context

Problem


Working Agenda

Questions & Suggestions


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Service-Oriented Architecture (SOA)

Successful architectural styles used for the development of software systems

SOA separates functions into distinct services

Services accessible over a network in order to allow users to combine and reuse them to

support business process

One or more services can offer the same or similar functionality to support a business activity

What are their differences?Quality attributesDuring design stage Ichoose the best one

Not always a guarantee

Some services can fail in execution

There are critical process which can not be stopped

Ok, but

OMG. What should

be the solution?

The system itself must find the best service and do

the binding without human interventionideally

Context


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It is a specialized entity that helps to its clients to buy, to sell and to rent the real

estate properties, like houses, apartments and offices.

Three main business process:

Property register Property to rent

Liquidation of payroll and commissions

Inmobiliaria de los Alpes

Context

Customer

Review

Acceptance of

Property

Property

Verification

Notification to

Offices

Property Register

Registration

Request

Study Case


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Self-Adaptivity(Quality Attributes based)

Improve the performance and

reliability of the system

Automatically and autonomously adapt

itself to respond to evolving internal and

external conditions without requesting any

intervention of the user

Context

Customer Review

DataCredito System Blacklist System

DataCredito

System Service

Default Service

DataCredito

System Service

DataCredito

System Service

Candidate Services

Different quality attributesWhos the best?

The Open Group Service

Integration Maturity Model

(OSIMM) Level 7

Inmobiliaria de los Alpes

Study Case


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Code-based implementation

Database-based implementation

A rule consists of three parts: The event part specifies the signal that triggers the invocation of the rule

The condition part is a logical test that, if satisfied or evaluates to true, causes the action

to be carried out

The action part consists of updates or invocations on the local data

if ( ( A.GetClientNumber() > 100 ) && ( CPU.Available() >= 0.1 &&

RAM.Available() >= 2 ) )

{A.SetInstanceNumber(120);

}

How to implement Self-Adaptability?

Traditional Approaches

Context


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Table of Contents

Context

Problem


Working Agenda



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These traditional approaches have two main limitations, and they are exposed here:

Self-adaptation mechanisms are not easy to neither understand nor read. How to

provide maintainability to them? Rules are of general purpose. Do not take in

consideration quality attributes.

A self-adaptive operation can be made but how to control it to avoid a violation over

a quality attribute? For example, a new service with lower response time but

without a security scheme.

How to provide a reliable way to run the tests? Trial an error for

every rule or every architectural decision? This is an inefficient

option. Besides, there's no guarantee of success.

Problem


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Table of Contents

Context

Problem


Working Agenda



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Architectural Model

Adaptation Rules

(MentaDSL)

Architectural Self-Adaptive

Model

Frascati

Self-Adaptive

Implementation

The proposal is a Model-Driven solution to enable the find and binding of the best service available supportedby self-adaptive features in SOA systems.

2. ECA Rules are not easy to neither understand nor read.

1. A self-adaptive operation can be made but how to control it to avoid a

violation over a quality attribute?

Proposal


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Archivol

Archivol is a research project focused on the study of software architecture and its relationship with

software development processes.

Key problems Software architecture are used only for documenting purposes

Software architecture doesn't evolve with software at the same pace

Visualizing and understanding architecture models is a complex task

FraSCAti

FraSCAti is an open-source Java-based implementation of the Service Component Architecture (SCA)

standard. The FraSCAti platform enables the dynamic introspection and modification of an SCA application.

This feature is of particular importance for designing and implementing agile SCA applications, such as

context-aware applications and autonomic applications.

openArchitectureWare (oAW)

oAW is a modular MDA/MDD generator framework implemented in Java(TM). It supports parsing of

arbitrary models, and a language family to check and transform models as well as generate code based on

them. Supporting editors are based on the Eclipse platform.At the core there is a workflow engine allowing

the definition of generator/transformation workflows. A number of prebuilt workflow components can be

used for reading and instantiating models, checking them for constraint violations, transforming them into

other models and then finally, for generating code.

Proposal


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Proposal

Architectural Model

Adaptation Rules

(MentaDSL)


Model

Frascati

Self-Adaptive

Implementation



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Architectural Model

Archivol

Service Oriented Architecture Model

Service Catalog, Quality

Attributes, Quality Scenarios

Proposal


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Architectural Model - Example

Proposal

Customer Review


DataCredito

System Service

DataCredito

System Service

DataCredito

System Service

Default Service

Candidate Services

Sn = DataCredito System Service n

S1

S2

S3

Archivol

Component S1

Component Type = SERVICEPROVIDER

Property Type = RESPONSETIME

Property Value = 1000 ms

Interface = iClinton

Component S2Component Type = SERVICEPROVIDER




Component S3

Component Type = SERVICEPROVIDER




Quality Scenario qualScePerformance

response = RESPONSETIME

responseMeasure

measureUnit = miliseconds

minValue = 0

maxValue = 1500


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Proposal

Architectural Model

Adaptation Rules

(MentaDSL)


Model

Frascati

Self-Adaptive

Implementation


1


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Adaptation Rules (MentaDSL)

Behavior, quality

attributes, metrics

ECA-QS

Menta MM

conformsTo

MentaDSL

Engine

MentaDSL

Quality Scenario-based

In other words, in response to this event, evaluate the condition, based

on quality scenarios and, take the defined action

Rules Model

Proposal

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Example of MentaDSL

Proposal

includeScenario qualScePerformance

includeScenario qualSceAvailability

rule {ruleForConsumingClinton}

for consumer {Verify Service}

consuming interface {iClinton}

fulfilling qualityScenarios {qualScePerformance,

qualSceAvailability};

rule {ruleForConsumingDataCredito}

for consumer {Verify Service}

consuming interface {iDataCredito}

fulfilling qualityScenarios {qualSceAvailability};

violationScenario {violationTest_1}

rules {ruleForConsumingDataCredito,

ruleForConsumingClinton, ruleForConsumingDataCredito};

Quality scenarios defined during design stage

using Archivol

Rule name

Client requesting

some functionality

Consuming this

exposed interface

Fulfilling this

quality scenarios

To Check how the system will work

To Check that the system will behave as it is expected

To see different candidate architectures

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Architectural Model

Adaptation Rules

(MentaDSL)


Model

Frascati

Self-Adaptive

Implementation

Proposal


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Architectural Self-Adaptive Model

Architecture Model Adaptation Rules

Model

Several models conforms to

Archivol MM and represented

using Archivol_Candidate

package

Proposal

Violation Scenarios

Customer Review


DataCredito

System Service

DataCreditoSystem Service

DataCredito

System Service

Default Service

Candidate Services

S1

S2

S3

violationScenario {violationTest_1}

rules {ruleForConsumingDataCredit, ruleForConsumingClinton, ruleForConsumingDataCredito};

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Architectural Model

Adaptation Rules

(MentaDSL)


Model

Frascati

Self-Adaptive

Implementation

Proposal


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Architectural Self-Adaptive Model OSIMM 7

Architecture Model Adaptation Rules

Model

Self-Adaptive Models ready for

transformation Internal useFraSCAti

Generated

ProgramCode Generation

[1] Architecture Tradeoff Analysis Method SM

Proposal


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Table of Contents

Context

Problem


Working Agenda


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Experimentation & Validation

ECA System / Exception

The list of available services will be handled in a static way. It could be a file or a List held in memory. It could also offer an

entry sorting that can be useful to enhance the process.

If the validation fails, another service can be taking for the services list.

MENTA System

The service definition is done during the systems modeling stage.

CONSIDERATIONS

Consists of: Executing the selectd business process. The problems in the services should be introduced in a controlled way to be able

to extract statistical data.

Test duration: 33 request per minute, within a 2 hours frame.

Number of tests: 5

TEST EXECUTION

We want to demonstrate that our proposal of self healing based on quality scenarios, is effective to select the best service available

our of a predefined pool, to supply the user defined quality requirements and to improve the performance, availability and

confidence of a given system.

WHAT DO WE WANT TO PROVE?


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Table of Contents

Context

Problem


Working Agenda


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MentaDSL definition

Mapping between MentaDSL and MentaMM

Transformations between MentaMM and ArchivolMM

Generation of candidate architectures

Generation of the internal model ready for transformation

Generation of the application code in FraSCAti

Validation and experimentation

Thesis document

Working Agenda


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Table of Contents

Context

Problem


Working Agenda


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Carlos Cetina, Pau Giner, Joan Fons & Vicente Pelechano. A Model-Driven

Approach for Developing Self-Adaptive Pervasive Systems. Models at run-

time 08 Workshop in conjunction with MODELS (Models@run-time). Touluse,

France. 2008

Franck Chauvel and Olivier Barais and Jean-marc Jzquel and Isabelle Borne

and Universit De Rennes. A Model-Driven Process for Self-Adaptive

Software. In 4th European Congress ERTS Embedded Real-Time Software.

2008

Adriana Vargas Cetina e Ismael Meja Useche. "Una Aproximacin Basada en

Modelos y Aspectos para Expresar Adaptaciones Dinmicas en

Arquitecturas Orientadas a Servicios. Caso Tongo". Master Thesis. 2008

Related Work

architectural models in a quality scenario-based analysis for self-adapting systems

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