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<< Part 8 - Performance testing techniques | Approach for load testing >>
<< Part 8 - Performance testing techniques | Approach for load testing >>

Load testing Web applications

Chapter 17 ­ Load-Testing Web Applications
Objectives
·
Understand the key concepts of load testing.
·
Learn how to load-test a Web application.
Overview
This chapter explains how to load-test a Web application. Load testing helps to identify
the maximum operating capacity of an application as well as any bottlenecks that might
interfere with its operating at capacity. The basic approach to performing load testing on
a Web application is:
1.
Identify the performance-critical scenarios.
2.
Identify the workload profile for distributing the entire load among the key scenarios.
3.
Identify the metrics that you want to collect in order to verify them against your
performance objectives.
4.
Design tests to simulate the load.
5.
Use tools to implement the load according to the designed tests, and capture the
metrics.
6.
Analyze the metric data captured during the tests.

By using an iterative testing process, these steps should help you achieve your
performance objectives.

There are many reasons for load-testing a Web application. The most basic type of load
testing is used to determine the Web application's behavior under both normal and
anticipated peak load conditions. As you begin load testing, it is recommended that you
start with a small number of virtual users and then incrementally increase the load from
normal to peak. You can then observe how your application performs during this
gradually increasing load condition. Eventually, you will cross a threshold limit for your
performance objectives. For example, you might continue to increase the load until the
server processor utilization reaches 75 percent, or when end-user response times exceed 8
seconds.
How to Use This Chapter
Use this chapter to understand the key concepts of load testing and the steps involved in
load-testing Web applications. To get the most from this chapter:
·
Use the "Input" and "Output" sections to understand the key inputs for load testing a
Web application and the key outcomes of doing so.
·
Use the "Approach for Load Testing" section to get an overview of the approach for
load testing a Web application, and as quick reference guide for you and your team.
·
Use the various steps sections to understand the details of each step involved in load-
testing a Web application.