Come with me. Cloud Computing (2) YARN

Introduced

The Apache Hadoop yarn is added to the Hadoop Common (core libraries) as a subproject of Hadoop, Hadoop HDFS (storage) and Hadoop MapReduce (the MapReduce implementation), it is also the top project of Apache.

In Hadoop 2.0, each client submits various MapReduce applications to the MapReduce V2 framework running on yarn. In Hadoop 1.0, each client submits a maprecude application to the MapReduce v1 framework.

Both types of APIs refer to the Maprecude framework available to developers to create MapReduce applications. The Org.apache.hadoop.mapred API is the earliest API that is most widely used in the creation of MapReduce applications. Any MapReduce v1 application developed using the Mapred API can be submitted to the MapReduce V2 framework running on yarn and run in the framework. In this case, there is no need to modify the MapReduce application.

The difference between hadoop1.0 and 2.0

A direct look at the picture will be more clear:

As part of hadoop2.0, yarn has the ability to manage resources, so it can use multiple new engines. Using yarn, you can run multiple applications on Hadoop, as shown in the following diagram:

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