1. how hadoop transaction is different form oracle transaction and also how read and write anatomy of Hdfs is different from oracle databases ?
2. how to transfer data from one datanode to another datanode ?
3. how nodes communicate each other ?
4.what is logical split ?
5.if datanode goes down how the blocks of that data node shift to another active datanode ?
6.what are the major components of an algorithm used by namenode to allocate location of block on different datanode ?
7.how to scale cluster configuration for particular data ?
8.how to design hadoop cluster to store 200 TB of data (resource,configuration&no of nodes.) ?
9. write an algorithm in which namenode decide to get the location of datanode to store block ?
10. what is job of OutputCollector ?
11. in which case we use split size greater then block size ?
12. write down the difference between mapr and maptask ?
13) write a job of combiner /what is a job compiler ?
14) write a mapreduce program , to introduce combiner class ?