Killswitch

Goose provides a killswitch mechanism to programmatically stop a load test when specific conditions are met. This is useful for protecting your systems and ensuring tests stop automatically when problems are detected.

To stop a run when a metric crosses a limit, such as a percentile response time or the error rate, use a threshold instead of writing the check.

When the killswitch is triggered, Goose logs Killswitch triggered: with the reason and stops the run as for Ctrl-C: users stop, test_stop runs, every report is written, and the run is recorded as canceled with the reason given. Under --no-autostart too, a killswitch stop then shuts Goose down rather than returning it to Idle, though a connected dashboard can keep it up until Quit, as at the end of an autostarted run. Only the first reason is kept: later calls change nothing until Goose clears the killswitch as the next run starts.

A killswitch fired by your own code, as below, is not an error in itself: execute() returns Ok with the metrics of the run so far, unless a threshold fails when the run ends.

Common Use Cases

• Health Check Integration: Monitor system health endpoints and stop on failure
• Resource Exhaustion Detection: Stop when detecting connection pool or memory issues
• Sitemap Traversal Completion: Stop after fully crawling a site’s pages
• Data Set Processing: Stop when all test data has been consumed
• External Signal Integration: Stop based on monitoring system alerts

Example: Service Unavailable Detection

#![allow(unused)]
fn main() {
use goose::prelude::*;

async fn check_availability(user: &mut GooseUser) -> TransactionResult {
    let goose = user.get("/api/endpoint").await?;

    // Stop the test if server returns 503 Service Unavailable
    if let Ok(response) = goose.response {
        if response.status() == 503 {
            goose::trigger_killswitch("Server returned 503: Service Unavailable");
        }
    }

    Ok(())
}
}

You can also check if the killswitch has been triggered using goose::is_killswitch_triggered() to conditionally execute cleanup code or skip certain operations.

goose::reset_killswitch() clears it. Goose calls it itself as each run starts. A test suite that runs several load tests in one process can call it after a test that triggered the killswitch, so the tests after it are not canceled.