Performance engineering of SDL/MSC systems

The invention relates to a method of generating a performance model from a functional model of a system comprising a plurality of co-operating and distributed hardware and software entities in order to provide a service to at least one user. The inventive method comprises the following steps consisting in: dividing the requests that are representative of the system into a finite number of groups and, for each group of requests, identifying the corresponding execution stream; formalising the execution streams using a notation which can be used to demonstrate (i) the causal relations between the different system software entities involved in the execution stream and (ii) the data that characterise the resource consumption of the system; producing an intermediate model; and automating the transformation of the intermediate model produced into a performance model.

Method of generating a performance model from a functional model

Publisher Summary This chapter describes the performance message sequence charts (PMSCs), an extension of message sequence chart (MSC)-96 to include performance aspects into the MSC language The language extension allows for the cospecification of functional and performance aspects This joint specification of functional and performance aspects eases the task of software engineers PMSC supports the formal specification of a variety of aspects related to performance This includes performance requirements, resource requirements, the specification of the available resources as well as the specification of the mapping of the MSC instances on the available resources To support the use of tools based on MSC-96, the language extensions are embedded in comments of the original MSC-96 language The cospecification based on MSC rather than on Specification and Description Language (SDL) supports the early evaluation of the performance of the system

An Annotational Extension of Message Sequence Charts to Support Performance Engineering

In various domains, performance evaluation has proved very valuable, especially when done at early stages of the development process; the simulation technique, in particular, combines good properties (flexibility, low-cost, relevance of results) for the prediction of software systems performance However, too often performance engineering is kept separate from the design process of software systems We try to analyze reasons for that, and discuss ways to better motivate designers to tackle performance evaluation We then present an approach that aims at producing performance models from design-oriented specifications (based on scenario and/or automata formalisms, such as MSC/SDL) The approach is well adapted to the study of service platforms, and targets basic queuing networks that offer a flexible and powerful framework for modeling performance, as well as mature simulators on the market

Looking for better integration of design and performance engineering

This paper presents a system theoretical approach which should ease systems architecting. This approach makes architectural design decisions explicit, and by using simulation the interrelations between different architectural design decisions can be determined. In that way an early feedback which reduces the risk of not meeting the requirements can be realized. Additionally, reuse and exchange of architectures is supported. A tool environment is presented which allows for the partial application of this approach.

Hierarchical architectural design, simulation and evaluation

Up to now no tool is available on the market that allows functional design and performance analysis within the same environment. Mostly new models have to be built to do performance analysis. This approach is time consuming and erroneous. To overcome this awkward situation two tools, namely GEODE/SDL a typical design tool and SES/workbench a typical simulation tool were coupled. The resulting design and simulation environment will allow the designer to make multiple iterations between functional and performance validation, and therefore the quality of the system design will be improved. Additionally the risk not to meet e.g. some of the performance requirements will be reduced dramatically.

A. Simma

Papers

EaSy-Sim: A Tool Environment for the Design of Complex, Real-Time Systems