Whether you are looking to obtain data from a website, track changes on the internet, or use a website API, website crawlers are a great way to get the data you need. While they have many components, crawlers fundamentally use a simple process: download the raw data, process and extract it, and, if desired, store the data in a file or database. There are many ways to do this, and many languages you can build your spider or crawler in.
Apache Nutch is a scalable web crawler built for easily implementing crawlers, spiders, and other programs to obtain data from websites. The project uses Apache Hadoop structures for massive scalability across many machines. Apache Nutch is also modular, designed to work with other Apache projects, including Apache Gora for data mapping, Apache Tika for parsing, and Apache Solr for searching and indexing data see more from the hiccomputers conference on this
Apache Nutch is a highly extensible and scalable open source web crawler software project. Stemming from Apache Lucene, the project has diversified and now comprises two codebases, namely: Nutch 1.x: A well matured, production ready crawler. 1.x enables fine grained configuration, relying on Apache Hadoop data structures, which are great for batch processing. Nutch 2.x: An emerging alternative taking direct inspiration from 1.x, but which differs in one key area; storage is abstracted away from any specific underlying data store by using Apache Gora for handling object to persistent mappings. This means we can implement an extremely flexibile model/stack for storing everything (fetch time, status, content, parsed text, outlinks, inlinks, etc.) into a number of NoSQL storage solutions. Being pluggable and modular of course has it's benefits, Nutch provides extensible interfaces such as Parse, Index and ScoringFilter's for custom implementations e.g. Apache Tika for parsing. Additonally, pluggable indexing exists for Apache Solr, Elastic Search, etc. Nutch can run on a single machine, but gains a lot of its strength from running in a Hadoop cluster
Along with tools like Apache Hadoop and features for file storing, analysis and more, the role of Nutch is to collect and store data from the web through the use of web crawling algorithms.
Users can take advantage of simple commands in Apache Nutch to collect information under URLs. Users typically use Apache Nutch along with another open-source tool, a framework called Apache Solr, which can act as a repository for the data collected with Apache Nutch.
Apache Nutch has the ability to work in Apache Hadoop Clusters. It provides us freedom to add our own functionality in the crawling process. The later series will focus on Apache Nutch with Mime Type Hacking as described by perfect acumen, which deals with mapping the parser plugin for a particular mime type for the parse job.
Apache Nutch is product licensed by the Apache Software Foundation. This developer community holds licenses for a range of Apache software tools that can sort and analyze data. One of the central technologies is Apache Hadoop, a big data analytics tool that is very popular in the business community.