What is marian?

Marian is a search engine built specifically for documentation. It runs as a web service that listens for search queries and returns matching results from a collection of documents you provide. MongoDB uses it to power the search bar on their documentation site, so when someone searches for a term like "aggregation pipeline," this is the tool finding and ranking the relevant pages. To get it running, you point it at a folder containing JSON files, either on your local machine or in Amazon's cloud storage (S3). Each JSON file describes a set of documents, including each document's title, a text snippet, a preview, and the URL where the full document lives. When the service starts up, it reads all these files into memory. From there, it sits on port 8080 waiting for someone to hit its search endpoint with a query. The service keeps things simple with three main endpoints. A search endpoint takes a query string and returns matching documents. A status endpoint reports whether the service is healthy. A refresh endpoint tells the service to rescan its source folder, which is useful when you have updated your documentation and want the search results to reflect the latest changes without having to restart the whole service. This project would be useful for teams that publish documentation and want a dedicated search experience for it, rather than relying on something like Google. A startup with a developer-facing API, for example, could use it to let users search through their technical guides. The document structure it expects, with headings, tags, and slugs, suggests it is tailored for structured content rather than random web pages. The README does not go into detail about the underlying search technology or how results are ranked. It does note that you can control how many background worker processes run using a simple environment variable, and it requires Node.js version 8 or later. Overall, it appears to be a straightforward, lightweight approach to documentation search rather than a heavy enterprise platform.