Getting Started With Apache Hadoop

Sometimes, it may be impossible to store data and analyze it using our traditional system.
Apache Hadoop
As Apache Hadoop suggests,
The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-availability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-available service on top of a cluster of computers, each of which may be prone to failures.
There are number of features explained in this refcard, which are listed below. 
  • Introduction
  • Design Concepts
  • Hadoop Components
  • HDFS
  • YARN
  • YARN Applications
  • Monitoring YARN Applications
  • Processing Data on Hadoop
  • Other Tools From the Hadoop Ecosystem
  • Additional Resources
You can download the refcard from below link.