What stored in HDFS?
when hadoop enter in safe mode?
Explain the core components of hadoop?
What problems can be addressed by using Zookeeper?
What are sink processors?
What infrastructure do we need to process 100 TB data using Hadoop?
What are the different types of Znodes?
What do sorting do?
Explain the hadoop-core configuration?
What is column families? What happens if you alter the block size of ColumnFamily on an already populated database?
Why we cannot do aggregation (addition) in a mapper? Why we require reducer for that?
Which command is used for the retrieval of the status of daemons running the hadoop cluster?
What does /var/hadoop/pids do?