Unlock the Power of Load Testing with Artillery
In today’s fast-paced digital landscape, web-based software must be efficient and capable of handling massive user bases. Load testing is a crucial performance test strategy that measures application speed and monitors application behavior under a virtually created user load. In this tutorial, we’ll delve into the features of the Artillery test runner and guide you on writing load test suites for your Node.js applications.
What is Artillery and How Does it Work?
Artillery is a free, open-source, fully-featured, cloud-based load testing platform written in JavaScript. It works as a traditional, minimal CLI program and only requires a newer Node.js runtime as an installation dependency. Artillery is both language- and tech stack-agnostic, allowing it to run load tests for web services written using any programming language.
Key Features of Artillery
- Test Any Stack: Artillery can run load tests for web services written using any programming language.
- Better CI/CD Support: Artillery offers pre-developed, Dockerized CI/CD server steps to run Artillery load test suites on the cloud.
- Modern Scalability: Artillery supports distributed testing, speeding up test runs by running parallel test suites on remote workers.
- Extensions and Integrations: Artillery internally uses an extendable and customizable project structure, allowing developers to extend and customize it.
Demo: Node.js Load Testing with Artillery
Let’s use Artillery practically for load testing with a sample Node.js web service. We’ll write a load test suite for a RESTful Node.js API that uses a MySQL database instance.
Setting Up the Node.js Backend API
We’ll create a sample web service to test with Artillery. The sample web service requires Docker, so make sure your development machine has a newer Docker version with Docker Compose.
Installing Artillery
We can install the artillery npm package globally to add the artillery command to our developer environment.
Writing Your First Load Test Case
The Artillery CLI lets you run a quick load test with the quick subcommand without a test script, but load testing a production-grade app typically requires a well-defined test runner configuration in a test script file.
Using Plugins for Metrics and Data Assertion
We can inspect the final Artillery summary report to get an idea about the web service’s performance, but it’s a general practice to print the pass/fail status of a test suite. Artillery offers inbuilt ensure and expect plugins for metrics and data assertion, respectively.
Creating a Load Test Suite
We’ll turn our simple load test script into a complete test suite that is good enough to accomplish a proper load test for the sample web service.
Generating HTML Reports
Artillery offers the report subcommand to generate an HTML report based on output JSON reports.
Running Artillery Load Test Suites on CI/CD Servers
Artillery can run tests on popular cloud CI/CD platforms via a Dockerized instance or directly, via the Artillery npm package commands.
Sending Metrics to Third-Party Monitoring Tools
Artillery can send metrics to popular cloud monitoring platforms like AWS CloudWatch via the publish-metrics plugin.
Load Testing with Authentication
For demonstration purposes, we used a sample public API that doesn’t contain any authentication strategy. However, almost all production RESTful APIs are protected with a popular authentication/authorization strategy.
Using Artillery to Improve Node.js App Performance
We can use load test reports to analyze and identify our web service’s performance issues. Let’s discuss some example scenarios where we can use Artillery reports to improve Node.js app performance.
- Using a Caching Solution: Caching helps us speed up data access times in computing modules.
- Database Optimization: Database design and configuration also affect your app performance.
- Code Refactoring: In some scenarios, we can fix performance issues by refactoring code to optimize algorithms, change third-party APIs, etc.
Advanced Artillery Configurations and Usage
Artillery can load test both HTTP and WebSocket protocols. WebSocket testing requires using the ws engine, which implements five communication actions for the flow segment: connect, send, think, loop, and function.
In conclusion, Artillery is a powerful load testing tool that helps developers identify performance issues and improve Node.js app performance. Its simplicity, productivity, and developer-friendliness make it competitive with other alternative load test runners.