For other tutorials and index of tutorials in this series click here : Tutorial : Hadoop -- Main Thread

Hello guys. Once you have an idea of what Hadoop and Big Data really are, lets have a look at the next important thing and that is to understand some of the terminologies that will be used in future tutorials.

Node :

A node is just a computer system typically a non enterprise hardware capable of storing data. Please note that it is a combination of nodes that lets Hadoop run with each node performing several functionality which I will go through in later tutorials. Diagrammatically a node is just another computer system as below




Rack :

We can add several nodes one after another and this collection of nodes is termed as a Rack. A rack is typically a collection of 30 to 40 nodes physically aligned close to each other and connected via the same network switch.


Important note: Network bandwidth any two nodes on a rack is greater than network bandwidth between two nodes on different racks.

Cluster:

A Hadoop Cluster or a Cluster is a collection of Racks.



So, these were the basic terminologies that must be understood in order to proceed further Do drop in comments in case you have any doubts.

Check in the Main thread here for links to other tutorials : Tutorial : Hadoop -- Main Thread