How to compress mapper output in Hadoop?

676

What can be optimum value for Reducer?

947

What are the advantages of using map side join in mapreduce?

646

What MapReduce framework consists of?

1094

Explain the sequence of execution of all the components of MapReduce like a map, reduce, recordReader, split, combiner, partitioner, sort, shuffle.

650

What is a scarce system resource?

653

what is Speculative Execution?

832

when do reducers play their role in a mapreduce task?

616

Where the mapper's intermediate data will be stored?

638

How does Hadoop Classpath plays a vital role in stopping or starting in Hadoop daemons?

710

what is the Hadoop MapReduce APIs contract for a key and value class?

668

How to configure the number of the Combiner in MapReduce?

625

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

651

What is heartbeat in hdfs? Explain.

681

How does inputsplit in mapreduce determines the record boundaries correctly?

647