The Hadoop ecosystem
Apache Hadoop is a very popular software framework for distributed storage and distributed processing on a cluster. Its strengths are in the price (it's free), flexibility (it's open source, and although being written in Java, it can by used by other programming languages), scalability (it can handle clusters composed by thousands of nodes), and robustness (it was inspired by a published paper from Google and has been around since 2011), making it the de facto standard to handle and process big data. Moreover, lots of other projects from the Apache foundation extend its functionalities.
Architecture
Logically, Hadoop is composed of two pieces: distributed storage (HDFS) and distributed processing (YARN and MapReduce). Although the code is very complex, the overall architecture is fairly easy to understand. A client can access both storage and processing through two dedicated modules; they are then in charge of distributing the job across all theorking nodes:
All the Hadoop...