Valutazione delle prestazioni di Architetture Software con specifica UML mediante QN multiclasse

Moreno Marzolla

Dipartimento di Informatica

Università Ca' Foscari di Venezia

Riunione FIRB/PERF—1/2 dicembre 2004

Software Performance Modeling

Software

Model

Performance

Results

UML

Model

Performance

Model

Perf. Model

Evaluation

Modeling

Algorithm

Feedback

Simulation

Model

Simulation

Execution

QN

Model

Model

Evaluation

Performance Modeling Framework

Annotated UML Model

Performance Results

Simulation

Model

Sim Model

Execution

QN

Model

QN Model

Evaluation

Performance Modeling with multiclass QN

Starting point

Use Case diagrams (workloads)

Deployment diagrams (hardware model)

Activity diagrams (system execution model)

Target notation

Mixed Multiclass QN model

Use Case diagrams	⇨ Workloads

Deployment diagrams	⇨ Service centers

Activity diagrams	⇨ Topology

Why?

Performance model generation can be done efficiently

O( #transitions + #action states )

Performance model can be solved efficiently

If some constraints are satisfied

The approach uses standard UML SPT profile annotations

Can be integrated with existing software performance modeling frameworks based on the profile

Translating UC diagrams

<<PAopenLoad>>

<<PAclosedLoad>>

λ

Translating Activity diagrams
the easy case

A1

A2

A3

R1

R2

R3

R1

R2

R3

Translating Activity diagrams
the difficult case

A1

A2

A3

R1

R2

R1

R2

Outline of the transformation algorithm

Translate one Activity diagram at a time

Each Activity diagram corresponds to a single chain

Resources correspond to service centers

Translate an Activity diagram as follows

All actions requesting service from the same resource receive a unique label in the range [1..k]

If there is a transition with probability p from an action with label r requesting service from resource i to an action with label s requesting service from resource j

Set P[i,r,j,s] = p

Example

p

1-p

1-p

p

2003-11-14T11:12:33