What happens if the number of reducers is 0 in Hadoop?

458

What happens if you don?t override the mapper methods and keep them as it is?

426

What is a combiner in hadoop?

479

What is the key difference between NameNode and DataNode in Hadoop?

449

How many datanodes can run on a single Hadoop cluster?

406

What is Slot in Hadoop v1? Why was it removed from Hadoop v2?

469

Can I set the number of reducers to zero?

375

Is it possible to have hadoop job output in multiple directories?

406

What is TextInputFormat in Hadoop?

473

Explain how do you overwrite replication factor?

405

Give a brief overview of Hadoop history?

384

Which database is used in hadoop?

449

What happen on the namenode when a client tries to read a data file?

429

If no custom partitioner is defined in Hadoop then how is data partitioned before it is sent to the reducer?

421

What are the main components in Hadoop Eco-System and what are their functions ?

445