Hadoop 2: Distributed Computing Framework for Big Data

Hadoop 2 is a distributed computing framework and open-source software platform used for storing, managing, and processing large datasets across a cluster of computers. It's the second major version of Hadoop and includes several new features and improvements over the previous version, Hadoop 1.x.

Some of the most significant changes in Hadoop 2 include:

1. YARN (Yet Another Resource Negotiator) - a new resource management system that enables Hadoop to support multiple processing models and workloads beyond just MapReduce.
2. High Availability - Hadoop 2 introduced a new feature that allows for NameNode failover, ensuring that the cluster remains available even if one of the NameNodes fails.
3. Federation - this allows for multiple Hadoop clusters to be managed as a single entity, making it easier to scale and manage large datasets.
4. Improved scalability - Hadoop 2 includes several improvements in terms of scalability, including support for larger clusters and more concurrent tasks.

Overall, Hadoop 2 represents a significant improvement over the previous version, providing greater flexibility, scalability, and reliability for big data processing.