MapReduce Cloud Computing Question:
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.
| Previous Question | Next Question |
| Can you explain what you understand by speculative execution? | Do you know how is MapReduce related to cloud computing? |