Crawling data with Memorious
Memorious is the web crawling framework that is part of Aleph toolkit. It can be used to periodically retrieve structured and unstructured data from the web and load it into Aleph.
Memorious (named after Funes the Memorious) is a light-weight distributed web scraping toolkit. It can:
- Maintain an overview of a fleet of crawlers
- Scrape and store both structured and unstructured data from the web
- Load the scraped data to Aleph in a variety of ways
- Schedule crawler execution in regular intervals
- Store execution information and error messages
- Distribute scraping tasks across multiple machines
- Make crawlers modular and simple tasks re-usable
- Get out of your way as much as possible
Memorious management interface
Memorious has a neat user interface to monitor the status of your crawler fleet at a glance. The interface also lets you start, stop and inspect crawlers with ease.
How it works
Memorious crawlers consist of a YAML configuration file and some (optional) Python functions to define crawler operations. Some built-in utility operations already come packaged with Memorious. For example, frequent operations like making HTTP requests, writing data into a database - can be done using built-in operations provided by Memorious. Memorious can also provide handy utilities to load the scraped data to Aleph for further processing.
A really simple crawler configuration in Memorious might look like this:
# Scraper for the OCCRP web site. name: occrp_web_site description: 'Organized Crime and Corruption Reporting Project' # Uncomment to run this scraper automatically: # schedule: weekly pipeline: init: # This first stage will get the ball rolling with a seed URL. method: seed params: urls: - https://occrp.org handle: pass: fetch fetch: # Download the seed page method: fetch params: # These rules specify which pages should be scraped or included: rules: and: - domain: occrp.org handle: pass: parse parse: # Parse the scraped pages to find if they contain additional links. method: parse params: # Additional rules to determine if a scraped page should be stored or not. # In this example, we're only keeping PDFs, word files, etc. store: or: - mime_group: archives - mime_group: documents handle: store: store # this makes it a recursive web crawler: fetch: fetch store: # Store the crawled documents to a directory method: aleph_emit params: collection: occrp_web_site
To learn more about Memorious, you can: