Cost Optimization Strategies for Running Cucumber Tests on AWS Device Farm

Running automated tests on real devices is a critical part of ensuring the quality of mobile applications. AWS Device Farm provides a robust and scalable environment to perform such tests. However, costs can quickly escalate if not managed properly. In this blog post, we’ll explore several cost optimization strategies for running Cucumber tests on AWS Device Farm, aiming to help software engineers, AWS engineers, and automation engineers get the best value from their testing budget.

Understanding AWS Device Farm

AWS Device Farm is a cloud-based service that allows developers to test their applications on a wide range of real devices hosted by AWS. It supports various frameworks, including Appium, Calabash, and Cucumber for behavior-driven development (BDD) testing.

Cost Structure

AWS Device Farm charges based on:

1. Device Minutes: The time a device is used for testing.
2. Instance Minutes: The time a virtual device instance is running.
3. Test Packages: Additional charges for complex test packages.

Understanding these costs is crucial for optimizing expenses.

Strategy 1: Parallel Testing

Explanation

Running tests in parallel can significantly reduce the total test execution time. AWS Device Farm supports parallel execution, which means you can run multiple tests on multiple devices simultaneously.

Implementation

In your Cucumber project, you can configure parallel execution using a test runner like JUnit. Here’s an example:

JUnit Runner Example:

import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import org.junit.runners.Suite.SuiteClasses;

@RunWith(Suite.class)
@SuiteClasses({
    TestClass1.class,
    TestClass2.class,
    TestClass3.class
})
public class ParallelTestRunner {
    // This will run tests in parallel
}

AWS Device Farm Configuration: When setting up your project in AWS Device Farm, specify the number of device slots you want to use for parallel testing.

Strategy 2: Optimizing Test Duration

Explanation

Reducing the duration of individual tests can lower the device and instance minutes used. This involves writing efficient tests and minimizing unnecessary steps.

Implementation

1. Avoid Hardcoded Waits: Use dynamic waits instead of hardcoded sleep statements.

WebDriverWait wait = new WebDriverWait(driver, 10);
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("element_id")));

2. Reuse Setup Code: Initialize common setup steps once rather than repeating them in each test.

@BeforeClass
public static void setUp() {
    // Initialize WebDriver and other setup steps
}

3. Parallel Execution in Cucumber: Utilize Cucumber’s built-in parallel execution features.

@CucumberOptions(
    features = "src/test/resources/features",
    glue = {"stepDefinitions"},
    plugin = {"pretty"},
    monochrome = true
)
public class RunCucumberTests {
    // This will run tests in parallel
}

Strategy 3: Test on Representative Devices

Explanation

Testing on every device can be cost-prohibitive. Instead, select a representative set of devices that cover the majority of your user base.

Implementation

1. Analyze User Data: Use analytics tools to determine the most popular devices and OS versions used by your customers.
2. Select Key Devices: Choose a mix of high, medium, and low-end devices from different manufacturers and OS versions.

AWS Device Farm Configuration: When creating a new device pool in AWS Device Farm, add only the selected representative devices.

Strategy 4: Scheduled Test Runs

Explanation

Schedule tests during off-peak hours when device usage rates might be lower, potentially reducing costs.

Implementation

1. AWS CLI: Use the AWS CLI to schedule tests.

aws devicefarm schedule-run --project-arn <project-arn> --device-pool-arn <device-pool-arn> --name "Scheduled Run" --test testSpecName=<test-spec-name>,type=APPIUM_NODE,testPackageArn=<test-package-arn>

2. Crontab: Use crontab for scheduling on Unix-based systems.

0 2 * * * /path/to/aws devicefarm schedule-run --project-arn <project-arn> --device-pool-arn <device-pool-arn> --name "Scheduled Run" --test testSpecName=<test-spec-name>,type=APPIUM_NODE,testPackageArn=<test-package-arn>

Strategy 5: Leverage Test Artifacts

Explanation

Analyze test artifacts (logs, videos, screenshots) to identify and eliminate redundant or flaky tests, reducing the number of unnecessary re-runs.

Implementation

1. Download Artifacts: Use AWS CLI to download test artifacts for analysis.

aws devicefarm list-artifacts --arn <run-arn> --type FILE

2. Analyze and Optimize: Regularly review artifacts to optimize test scenarios.

Conclusion

By implementing these cost optimization strategies, you can significantly reduce the expenses associated with running Cucumber tests on AWS Device Farm. Parallel testing, optimizing test duration, selecting representative devices, scheduling test runs, and leveraging test artifacts are all effective methods to get the most value out of your testing budget.

If you found this article helpful and are interested in integrating Cucumber Automation Framework with AWS Device Farm, I suggest you check out some of the other articles I’ve written for this series:

• Running Parallel Tests with Cucumber on AWS Device Farm
• Creating Automated Mobile Tests with Cucumber and AWS Device Farm
• Cross-Browser Testing with Cucumber and AWS Device Farm

If you’re looking for a deeper dive into some of the concepts and specifics discussed in my article, feel free to reach out to me directly or as always you can checkout the official AWS Device Farm Developer Documentation for more information.