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What is a IdentityMapper and IdentityReducer in MapReduce ?

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Final answer:

An IdentityMapper reads input data and emits key-value pairs as is, while an IdentityReducer receives intermediate key-value pairs from mappers and emits them without any changes.

Step-by-step explanation:

IdentityMapper and IdentityReducer are classes in the MapReduce framework. They are used when the input and output keys and values of a MapReduce job are the same. The IdentityMapper class reads the input data and emits key-value pairs as is. It is the default mapper in MapReduce. The IdentityReducer class receives the intermediate key-value pairs from the mappers and emits them without any changes.

User Ori Yarden PhD
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