Standby Load Generator

Sends HTTP requests to a Standby Actor URL at a fixed interval and logs results. Designed to detect downtime during worker migrations — look for errors or gaps in the output.

Usage

$npx tsx src/main.ts <standbyUrl> [intervalMs=100] [durationSecs=300] [waitForResponse=true]

Parameters

Parameter	Default	Description
standbyUrl	(required)	Full Standby URL of the target Actor
intervalMs	100	Milliseconds between requests
durationSecs	300	How long to run
waitForResponse	true	Wait for each response before sending the next. Set to false for concurrent requests (use with caution — can generate large traffic)

Example

# Sequential (default) — safe, one request at a time
npx tsx src/main.ts "https://standby-target.dev.apify.net?delayMs=200" 100 300

# Concurrent — fires every 100ms regardless of response time
npx tsx src/main.ts "https://standby-target.dev.apify.net?delayMs=200" 100 300 false

Output

Prints a summary line every second:

[1s] seq=10 errors=0 runId=abc123 latency=45ms
[2s] seq=20 errors=0 runId=abc123 latency=12ms
[RUN ID CHANGED] seq=25 from=abc123 to=def456 latency=38ms
[3s] seq=30 errors=0 runId=def456 latency=10ms

At the end, prints a summary with total requests, errors, and all run ID transitions.

What to look for

• Zero errors through a migration = connection draining works
• Run ID transition = traffic moved to the replacement run
• Errors during transition = downtime detected