The map() method is called once for each key-‐value pair, and all the results for each mapper are collected and sent to the partitioner which breaks out results based on hashed key values.
What is meant by hashed key values?
We discuss map() and reduce() methods briefly in Lesson 1 of ESS 100 – Introduction to Big Data and Lesson 3 of ESS 101 – Apache Hadoop Essentials. We also cover the MapReduce paradigm in greater depth in DEV 301 - Developing Hadoop Applications. We're currently working on updating DEV 301, so we'll make sure hashed key values are explained in detail.
Onna Nelson Is this covered under any of training modules? Please check. Thank you.
Retrieving data ...