MapReduce Cloud Computing Question:
Download Questions PDF

When do reducers play their role in a mapreduce task?

Answer:

The reducers in a mapreduce job do not begin before all the map jobs are completed. Once all the map jobs are completed the reducers begin copying the intermediate key-value pairs from the mappers. Overall reducers start working as soon as the mappers are ready with key-value pairs.

Download Cloud Computing - MapReduce Interview Questions And Answers PDF

Previous QuestionNext Question
Can you explain what you understand by speculative execution?Do you know how is MapReduce related to cloud computing?