Search Engine

This is a single-node toy/demonstration of a search engine distributed system.

Components:

• Web Server
  • serves a simple html page with search input text box
  • on submit the query is logged to an analytics log and the top 10 search results ranked by TF-IDF are returned
• Analytics cron job
  • reads the analytics log and constructs a Trie with caching to serve autocomplete suggestions
• Web Crawler cron job
  • Builds an Inverted Index from scraped web pages starting with Hacker News as a seed url

Running

Prerequisites for running:

• make
• Docker
• A web browser

To run the application

1. make build
2. docker-compose up
3. Open a browser to localhost:3000
4. Start submitting queries
5. If you want to refresh the search index, run make inverted_index

Note: the autosuggest trie is refreshed every 30 seconds.

Development

Prerequisites for developing:

• Python/Pip

Create a virtual environment

python -m venv .venv

Install requirements

make install

Run tests

make test

TODO

• Move the web crawler cron job to docker-compose: unfortunately Selenium web_driver is currently not supported in the docker environment, so you'll have refresh the index yourself