Mention what is the Hadoop MapReduce APIs contract for a key and value class

Question

Can someone suggest the answer for the above question that what is the Hadoop MapReduce API's contract for a key and value class?

Answer 1

Hey,

For a key and value class, there are two Hadoop MapReduce APIs contract

• The value must be defining the org.apache.hadoop.io.Writable interface
• The key must be defining the org.apache.hadoop.io.WritableComparable interface