Enterprise Library Test Guide - Willy .Net

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Enterprise Library Test Guide
Scalability tests are extensions of performance tests. The outstanding characteristic
of a scalable application is that it only requires additional resources to operate under
additional loads instead of requiring extensive modifications to its code. The goals of
scalability testing are:
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To determine any performance gains the application block achieves with additional
system resources, such as CPUs or computers, or any additional external
resources, such as a SQL Server database or a disk array.
To identify any locking and contention problems that may not be detected by
performance tests.
Although performance affects how you determine the number of users that an application
can support, scalability and performance are two separate requirements.
Performance optimizations may reduce an application’s scalability and scalability
optimizations may reduce an application’s performance.
This chapter contains the following sections:
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Defining Performance Criteria. This section defines the performance criteria that
are used to test the application blocks. The performance criteria describe the
performance goals for the Enterprise Library in terms of system metrics and
transaction times. For example, a performance goal may be to have less than 10
locks per second. Another goal may be to have transaction times that are less than
250 milliseconds (ms).
Setting Up the Test Environment. This section describes the Enterprise Library test
environment.
Building Test Harnesses. This section describes how to create a test project, Web
tests, test harness script, and a load test.
Testing the Application Blocks. This section describes how each application block
was tested.
Detecting Performance Issues. This section describes the performance parameters
you should monitor to detect performance issues in the application blocks.
Measuring Performance. The section describes the performance metrics for the
application blocks. Examples include the amount of system resources each application
block uses and the transaction times for API calls. It also describes performance
counters you can use to measure performance.
Testing for Scalability. This section describes the objectives of the scalability tests
and analyzes the results for several application blocks.
Measuring Initialization Costs. This section describes how to measure the amount
of system resources and time necessary to prepare an application block so that it
can begin to execute requests.
Extrapolating Workload Profiles. This section describes how to use Little’s Law to
characterize workloads.
Debugging Memory Leaks. This section explains how to use the WinDbg debugger
to detect memory leaks.