Ragit
Ragit

Reputation: 125

hadoop: Reducer output to another Reducer

Is it possible to send output of a Reducer directly to another reducer if we want to group by the same key ( output of the first reducer )

Sometimes while chaining i observe that i am using a mapper just to read from input and copy same to output. Hence wondering idf it is possible to fed the output directly to reducer

Upvotes: 7

Views: 2641

Answers (1)

frail
frail

Reputation: 4118

Although you can chain map-reduce jobs, even mappers, together; as far as I know you can not chain reducers directly.

Internally you can chain mappers before reducer with ChainMapper and chain Mappers after reducer with ChainReducer.

Upvotes: 7

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