Apache YARN

• YARN:
• Yet Another Resource Negotiator
• YARN 
• is Hadoop's cluster resource management system.
• was introduced in Hadoop 2
• to improve the MapReduce implementation.
• but is general enough to support other distributed computing paradigms as well.
• YARN
• provides APIs for requesting and working with cluster resources.
• but these APIs are not typically used directly by user code.
• (Instead,) users write to higher-level APIs provided by distributed computing frameworks,
• which themselves are built on YARN and hide the resource management details from the user.

(There is a further layer of applications that build on the frameworks shown in the figure above. Pig, Hive and Crunch for examples)