---
title: "Build a breakpoint script | Grafana Labs"
description: "Build a breakpoint script with ramping-arrival-rate and abortOnFail."
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# Build a breakpoint script

If you completed the stress milestones, you already have degradation results or a documented clean run. Breakpoint testing is optional and runs on a dedicated stack when you want an approximate outer bound beyond that stress profile.

Breakpoint testing ramps load continuously toward high load until thresholds fail or the ramp ends: an approximate **outer bound**, not an operating target.

**Note:** On QuickPizza, the ramp often completes without abort. You still learn `ramping-arrival-rate` and `abortOnFail`. For your own stack, use a dedicated test environment and disable autoscaling on components you want to measure. Refer to [Breakpoint testing](/docs/k6/latest/testing-guides/test-types/breakpoint-testing/).

**Tip:** To see `abortOnFail` stop a run on QuickPizza, [run QuickPizza locally with Docker](https://github.com/grafana/quickpizza#run-locally-with-docker) and point `http.get(...)` at your local instance. You can use the same `breakpoint.js` script from this milestone to ramp a local instance to failure.

This milestone introduces the `ramping-arrival-rate` executor (RPS ramps over time) and `abortOnFail` thresholds (stop the run when conditions fail). For one-request scripts, iterations per second matches RPS.

To build a breakpoint script, complete the following steps:

1. In your code editor, create a new file named `breakpoint.js` and add the following imports:
   
   JavaScript ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy
   
   ```javascript
   import http from 'k6/http';
   import { check, sleep } from 'k6';
   ```
2. Define a scenario using the `ramping-arrival-rate` executor.
   
   The following example ramps from 0 to 200 iterations per second over 10 minutes, pre-allocating enough VUs to sustain the target rate. Plan for about **10 minutes of runtime** on the next milestone when you run this script as written. Shorten `duration` (for example to `3m`) while learning if you want a faster iteration.
   
   JavaScript ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy
   
   ```javascript
   export const options = {
     scenarios: {
       breakpoint: {
         executor: 'ramping-arrival-rate',
         startRate: 0,
         timeUnit: '1s',
         preAllocatedVUs: 500,
         maxVUs: 1000,
         stages: [
           { duration: '10m', target: 200 },
         ],
       },
     },
     thresholds: {
       http_req_duration: [
         {
           threshold: 'p(95)<2000',
           abortOnFail: true,
           delayAbortEval: '30s',
         },
       ],
       http_req_failed: [
         {
           threshold: 'rate<0.20',
           abortOnFail: true,
           delayAbortEval: '30s',
         },
       ],
     },
   };
   ```
   
   The `preAllocatedVUs` and `maxVUs` values avoid VU starvation during the ramp. `delayAbortEval` waits before abort evaluation so early noise does not stop the run; see [Thresholds](/docs/k6/latest/using-k6/thresholds/).
   
   **Note:** Adjust `target` and `duration` for your stack. If stress showed no degradation on QuickPizza, you may finish the full ramp without abort, which is still a valid result.
3. Add the default function with the same checks you’ve used throughout this path:
   
   JavaScript ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy
   
   ```javascript
   export default function () {
     const res = http.get('https://quickpizza.grafana.com');
   
     check(res, {
       'status is 200': (r) => r.status === 200,
       'response body is not empty': (r) => r.body.length > 0,
     });
   
     sleep(0.1);
   }
   ```
   
   The `sleep` value is shorter than in the stress test because the `ramping-arrival-rate` executor controls the request rate independently of VU think time.
4. If you are testing your own service, replace the URL in `http.get(...)` with your endpoint, then save `breakpoint.js`.

In the next milestone, you run this breakpoint test and read off the load at **test stop** (threshold abort or end of ramp).