A Step-By-Step Approach to Capacity Planning in Client/Server Systems
- Chapter 5 A Step-By-Step Approach to Capacity Planning in Client/Server Systems
- 2 Adequate Capacity
- 3 A Methodology for Capacity Planning in C/S Environments
- 4 Understanding the Environment
- 5 Workload Characterization
- 6 Workload Forecasting
- 7 Performance Modeling and Prediction
- 8 Development of a Cost Model
- 9 Cost/Performance Analysis
- 10 Concluding Remarks
- BIBLIOGRAPHY
In this chapter, authors Daniel Menasce and Virgilio A.F. Almeida start by providing a clear definition of what capacity planning means, and then present a methodology to help the capacity planner through the process of determining the most cost-effective system configuration and networking topology.
5.1 Introduction
Planning the capacity of a C/S system requires that a series of steps be followed in a systematic way. This chapter starts by providing a clear definition of what adequate capacity means. It then presents a methodology that leads the capacity planner, in a step-by-step fashion, through the process of determining the most cost-effective system configuration and networking topology. Investment and personnel plans follow as a consequence. The main steps of the methodology are: understanding the environment, workload characterization, workload model validation and calibration, performance model development, performance model validation and calibration, workload forecasting, performance prediction, cost model development, cost prediction, and cost/performance analysis.
The methodology presented here requires the use of three models: a workload model, a performance model, and a cost model. The workload model captures the resource demands and workload intensity characteristics of the load brought to the system by the different types of transactions and requests. The performance model is used to predict response times, utilizations, and throughputs, as a function of the system description and workload parameters. The cost model accounts for software, hardware, telecommunications, and support expenditures.
This chapter draws in part on material presented in [7] and Chap. 2 of [8]. Various steps of the methodology are discussed in further detail in subsequent chapters.