What is Hadoop Map Reduce? How it works?

Question

How a job works in YARN/Map Reduce? like navigation path.

Please check my understanding is right?

When the application or job or client starts, client communicate with Name node the application manager started on node (data node), Application manager communicates with Resource manager (on name node) to get resource.The resource are assigned to container. The job runs on Container which is JVM.

Answer 1

MAP Reduce is a framework initially created by Google read this white paper:
Map Reduce White Paper

It was developed for processing large amount of data (usually stored in a distributed file system like HDFS) to obtain useful pattern from it.

Hadoop is nothing but a collection of individual computers which use commodity hardware for storing large amount of data(usually big data) whose size is larger than a single computer's memory

For example,your computer has a memory of 500gb and mine another 500gb(imagine they are free) and you are provided with a data source of size 800gb

None of our systems are individually capable of holding this data so our idea is to combine the systems to get a total size of 1000gb

Now our data gets stored in this combined distributed file system known as hdfs-hadoop distributed file system

Now we may require to process our data like finding some useful pattern from it for that we use hadoop map reduce as an analytical platform

For more to know about how it works: