Hadoop cluster
- Any computer hardware which is working.
Rack
- A group of interconnected nodes.
Switch
- By using switch, communication is happening between the rack nodes.
- A group of interconnected Racks.
- Hadoop cluster contains the Group of Racks.
- Name node, Job Tracker, Secondary name node, Data nodes, task tracker & client all these presents in Rack.
- Name node is one per cluster.
- Data node and task tracker can exists many in cluster to store actual data and process the data.
Thanks for your time.
-Nireekshan