Introduction

Dynamic sampling intelligently groups similar pages and scans only a representative sample. This feature prevents performance issues when scanning sites with hundreds of similar pages like blogs, product catalogs, or user profiles.

Dynamic sampling is enabled by default with 5 samples per group.

How it works

When dynamic sampling is enabled, it will group paths into chunks based on their path tree.

For example, let's imagine we have a blog on our site and there are hundreds of blog posts. Scanning every blog post will take a long time and may even break Unlighthouse.

The path structure is /blog/{post}.

Unlighthouse will turn this path structure into groups based on the /blog prefix. By default, it will sample 5 paths starting with this prefix.

A sample being a random selection of paths within this group.

For example if we have the posts:

• /blog/post-a
• /blog/post-b
• /blog/post-c
• /blog/post-d
• /blog/post-e
• /blog/post-f
• /blog/post-g
• /blog/post-h
• /blog/post-i

After sampling, we may end up with the random selection:

• /blog/post-c
• /blog/post-d
• /blog/post-e
• /blog/post-h
• /blog/post-i

Usage

It is configured using the scanner.dynamicSampling option.

import { defineUnlighthouseConfig } from 'unlighthouse/config'

export default defineUnlighthouseConfig({
  scanner: {
    dynamicSampling: 10, // Number of samples per group (default: 5)
  },
})

Disable Dynamic Sampling

export default defineUnlighthouseConfig({
  scanner: {
    dynamicSampling: false,
  },
})

Alternatively, you can disable it using the CLI --disable-dynamic-sampling.