What is "stormcrawler"

StormCrawler is an open source collection of resources for building low-latency, scalable web crawlers on Apache Storm. It is provided under Apache License and is written mostly in Java (programming language).

StormCrawler is modular and consists of a core module, which provides the basic building blocks of a web crawler such as fetching, parsing, URL filtering. Apart from the core components, the project also provide external resources, like for instance spout and bolts for Elasticsearch and Apache Solr or a ParserBolt which uses Apache Tika to parse various document formats.

The project is used in production by various companies.