Can reducers and cartographers be with the same node data?

Question

I started reading about Big Data and Hadoop, so this question may seem very silly to you.

This is what I know.

Each handler processes a small amount of data and produces intermediate output. After that we have a random step and sort.

Now Shuffle = moving intermediate output to corresponding reducers, each of which deals with a specific key / keys.

So, can one Data Node have Mapper and Reducer code in it, or do we have different DNs for each?

Answer 1

• : HDFS (). Mappers Reducers (compute) , TaskTracker.

• : mapred.tasktracker.map.tasks.maximum mapred.tasktracker.reduce.tasks.maximum

, , , tasktracker , worktracker. , jobtracker .

, , node.

Answer 2

, , node. hashop node. hadoop node HDFS ( , ), node.

node.