What is hadoop? How hadoop is useful..

Question

in simple language

Answer 1

"Mastering Hadoop" e-book is for free today at packtpub.com:
https://www.packtpub.com/big-data-and-business-intelligence/mastering-hadoop

Answer 2

Hadoop is an open-source framework used for distributed storage and large-scale data ("big data") management and processing. It uses the MapReduce model to facilitate both fast data access and efficient processing.
One more advantage of Hadoop is that it handles computer failures well.

Answer 3

To understand hadoop,you need to first understand what is "Big Data".Big data as the name suggests are huge chunk of information that might consume memory in terms of 100s of Gb,pb and zb.For example tweets each seconds,Stock data,flight recorder data,youtube video feeds,etc.So to process that kind of huge data,you need hadoop.Hadoop is a framework/ecosystem that ingests these data and as per client demand processes these data.It makes use of two tier architecture master system (only one)and data nodes(multiple).Master nodes takes the client request and data nodes does the processing via map reduce program.
For more details you can visit Apache hadoop site