PARALLEL.MD

Parallel Execution

🧠You will learn

✅ How to create ridiculously fast test suites

✅ How to implement parallelization

In today's world, it's improbable to succeed without parallelization

"Once you have these automated tests, our analysis shows it’s important to run them regularly. Every commit should trigger a build of the software and running a set of fast, automated tests. Developers should get feedback from a more comprehensive suite of acceptance and performance tests every day. Furthermore, current builds should be available to testers for exploratory testing." (Nicole Forsgren PhD, Jez Humble, Gene Kim, Accelerate: The Science of Lean Software and DevOps: Building and Scaling High Performing Technology Organizations)

Try to run the current suite of tests:

mvn test -Dtest="E2ESolutionTests,VisualDataDrivenSolutionTests"

This is how long my tests took

241 sec/8 tests = 30 sec/test

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❓What's the problem with this approach?

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🏋️‍♀Implement parallelization

1. Go to pom.xml and add the following at the same level as the <dependencies> node

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.0.0-M5</version>
                <configuration>
                    <parallel>all</parallel>
                    <threadCountMethods>100</threadCountMethods>
                    <useUnlimitedThreads>true</useUnlimitedThreads>
                    <redirectTestOutputToFile>false</redirectTestOutputToFile>
                </configuration>
            </plugin>
        </plugins>
    </build>

2. In terminal run

mvn test -Dtest="E2ESolutionTests,VisualDataDrivenSolutionTests"

3. Login to saucelabs.com and watch tests run in parallel

My results

What we just achieved ✅💪

✅ 78% speed improvement in < 5 min

✅ 0 degradation to our test quality

✅ Enabled parallel scaling

📝Summary

✅ Parallel testing is awesome

Extra resources

Achieving 97% test suite run time improvement

⏭️Let's summarize