Testing Individual Response Times Under Load
Problem
You need to test that a single user’s response time is adequate under heavy loads.
Solution
Decorate your JUnit Test
with a JUnitPerf
TimedTest
to simulate one or more concurrent
users, and decorate the load test with a JUnitPerf
TimedTest
to test performance of the load.
Discussion
Testing whether each user experiences adequate response times under varying loads is important. Example 8-4 shows how to write a test that ensures each user (thread) experiences a 3-second response time when there are 100 simultaneous users. If any user takes longer than three seconds the entire test fails. This technique is useful for stress testing, and helps pinpoint the load that causes the code to break down. If there is a bottleneck, each successive user’s response time increases. For example, the first user may experience a 2-second response time, while user number 100 experiences a 45-second response time.
Example 8-4. Stress testing
package com.oreilly.javaxp.junitperf; import junit.framework.Test; import junit.framework.TestSuite; import com.clarkware.junitperf.*; public class TestPerfSearchModel { public static Test suite( ) {Test testCase = new TestSearchModel("testAsynchronousSearch");
Test timedTest = new TimedTest(testCase, 3000, false);
Test loadTest = new LoadTest(timedTest, 100);
TestSuite suite = new TestSuite( ); suite.addTest(loadTest); return suite; } public static void main(String args[]) { junit.textui.TestRunner.run(suite( )); ...
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