When is the reducers are started in a MapReduce job?

689

What are the various input and output types supported by mapreduce?

456

Explain what is the function of mapreduce partitioner?

463

Is it possible to rename the output file?

588

What are ‘maps’ and ‘reduces’?

494

Which Sorting algorithm is used in Hadoop MapReduce?

422

Which among the two is preferable for the project- Hadoop MapReduce or Apache Spark?

429

For a Hadoop job, how will you write a custom partitioner?

479

What is difference between a MapReduce InputSplit and HDFS block

479

What are the configuration parameters in the 'MapReduce' program?

490

In MapReduce, ideally how many mappers should be configured on a slave?

483

What is difference between an input split and hdfs block?

449

What is the difference between Job and Task in MapReduce?

460

How do Hadoop MapReduce works?

538

Explain the differences between a combiner and reducer

472