Franz Brosch 28/11/2011

WIR FORSCHEN FÜR SIE

The Palladio Component Model (PCM)

for Performance and Reliability Prediction

of Component-based Software Architectures

Franz Brosch28/11/2011

1. Foundations2. PCM overview3. Performance & reliability prediction4. PCM applications & further research

Outline

2

Software System Quality

3

FoundationsOverviewPrediction

Applications

Quality Requirements

Quality Requirements

Actual QualityActual Quality Product(Software System)

Product(Software System)

Requirements Specification

Requirements Specification

Software Development Process

Design-time Modeling & Prediction

4

Architectural model of acomponent-based software system

Prediction of expected quality PerformanceReliability…


Applications

Architectural Design Loop

5

PredictedQuality Metrics

Evaluation Feedback

Architectural Model

Estimation, Benchmark 25 ms

5 ms

10 ms

Annotated Architectural Model

Quality models(e.g. queueing networks

for Performance)

ModelTransfor-mation

Analysis / Simulation


Applications

The Palladio Approach

6

A Component Model

Multiple Analysis Methods

A Development ProcessAllocation

QoS Requirement Annotation

QoS Information Integration

QoS

Ana

lysi

s

System Architect

System Model Transformation

System Deployer Domain Expert

System Environment Specification

QoS Attribute Specification of Resources and

Connections

Use Case Analysis

Usage Model Refinement

Use Case Models

Scenarios(Activity Charts)

Component QoS Specification

(Data Dependencies,Resource Consumption)

Annotated System Architecture

Fully QoS Annotated System Architecture

QoS EvaluationModel

QoS Metrics

Results forQoS Metrics

Component Specs &Architecture

Component Specs & Architecture

Use Case Models

AnnotatedDeployment

Diagram Refined User

Model

SystemEnvironment

DeploymentDiagram

Component Developer

BusinessRequirements

QoS Evaluation

DeploymentDiagram


Applications

Component Quality Influences

7

User behaviour

Hardware

External Services

Code


Applications

PCM Developer Roles

8


Applications

Models and Analyses

9

DomainExpert

SystemDeployer

SoftwareArchitect

ComponentDeveloper

Transform

ation

Transformation

Java CodeSkeletons

Completion +Compilation

Transformation

QueueingNetwork

Simulation

Transformation

PerformancePrototype

Execution +Measurement

Part

of

Part of

Part of

Part of

PCMInstance


Applications

Markov ChainsAnalysis

PCM Bench

10


Applications

Comprehensive quality modeling approach Improved support for CBSE process Improved prediction accuracy

• Sophisticated usage model & usage propagation• Stochastic Expression language for specification of arbitrary

probability distributions and parametric dependencies Support for trade-off analyses Tool support available

PCM Features

11


Applications

Performance Prediction

12

<<Server>>

RDSEFF <<Network Link>> RDSEFF

Service Call

CPU HDD Memory

Resource demands Communication link latency & throughput

Hardware resource processing speed

System workload


Applications

Resource utilization

<<Server>>Response

time

Resource utilization

Responsetime

Resp.time

Throughput

Return

Quality models• Queueing network (evaluation through simulation)

Result metrics• Response times (system level / component level)• Throughput• Hardware resource utilization

Features• Developer roles, UML-like modeling, usage propagation• Multi-user scenarios with concurrent behavioral

specification• Arbitrary input distributions / full result distributions

Performance Prediction

13


Applications

Reliability Prediction

14

<<Server>> <<Server>>

RDSEFF <<Network Link>> RDSEFF

Service Call

ReturnCPU HDD Memory

Software failures Communication link failures

Hardware resource unavailability


Applications

P(SUCCESS)

Quality model• Set of absorbing discrete-time Markov Chains (DTMC)• Evaluation through analysis

Result metrics• Probability of successful execution of a usage scenario

(= 1 – POFOD) Features

• Developer Roles, UML-like modeling, usage propagation• Accurate modeling of control and data flow• Combined consideration of software reliability & hardware

availability

Reliability Prediction

15


Applications

PCM Applications: Research

16


Applications

PCM Applications: Industry

17


Applications

Further Research Directions

18

Architecture optimization Architecture reengineering Run-time prediction Maintainability Security Component certification


Applications

Thank You

19

Thank you!Thank you!

Franz Brosch 28/11/2011

Documents

Transcript of Franz Brosch 28/11/2011