How to resolve ioexception: cannot create directory, while formatting namenode in hadoop?
What are different hdfs dfs shell commands to perform copy operation?
did you maintain the hadoop cluster in-house or used hadoop in the cloud?
What happens to a namenode, when job tracker is down?
What mechanism does hadoop framework provides to synchronize changes made in distribution cache during runtime of the application?
How to configure hadoop to reuse JVM for mappers?
What if a namenode has no data?
What is Row Key?
What is Writable & WritableComparable interface?
Define a metadata?
What is a 'block' in HDFS?
Explain the basic difference between traditional rdbms and hadoop?
Where do you specify the Mapper Implementation?