Load Testing

This folder contains scripts and helpers for load testing Javabuilder. Load tests are instrumented via k6.

One time set up

• Install Docker

How to run

Run Locally

• Ensure docker is running. This usually entails opening Docker Desktop.
• Generate a random password for your session. Copy this password to configuration.js and jwt_helper.rb. Also update jwt_helper.rb with IS_LOAD_TEST = true. Do not commit or merge this password. If you do, immediately change your deploy of Javabuilder to no longer use it.
• Deploy an instance of Javabuilder with your changes.
• From this folder, run docker build -t load-testing . (You can use any name you would like in place of load-testing)
• Run docker run load-testing

Run on AWS

• See instructions in this document.

Customizing a Load Test

Load Configuration Options

In loadTest.js you can modify 2 basic parameters for the load.

The first is the user goal. This is the number of expected total Javabuilder users you would like to simulate. An important thing to note here is this is not the number of Virtual Users we will simulate during the test. The number of Virtual Users is the user goal divided by 30, as that is the highest load we saw historically based on number of users.

The second is the high load time. This is the time in minutes the test will run at its highest load. This time does not include a 2 minute manual ramp-up stage.

There is also a slightly more complex toggle, SHOULD_SLEEP. If this is set to true, requests will be spaced out at a specific interval, to simulate more realistic traffic. If it is set to false, requests will never sleep, which will ensure we have concurrent requests equal to the number of Virtual Users. If you want to simulate the highest possible load, use false here. If you do use false, you should not run the load test for very long, as you will get a lot of data (and send a lot of requests) from 5 minutes of high load.

Configure Student Code

If you would like to add new source code that the load test will upload to Javabuilder, add the JSON string to sources.js. An easy way to generate this data is to run Java Lab normally with your desired source code, then copy over the JSON from the content bucket. Then update loadTest.js to use your new sources object.

Add a Metric

We have many k6 metrics we calculate during a load test. If you would like to create a new one, initialize it with the other metrics, and track it wherever makes sense. The metric will automatically show up in the test summary so long as the value is not zero.

Change the script file

If you want to create a fully new load test script, you can substitute the new script name in the Dockerfile.

Further Details

If you need to do further customization, the k6 documention and API Guide detail the capabilities available to you.