Hadoop 1, can be I/O intensive, not suitable for interactive analysis, and constrained in support for graph, machine learning and on other memory intensive algorithms.
Hadoop 2 has several advantages which is explained in a simple way in the below document
Hi, Thanks for your reply. I know the differences between hadoop 1 and hadoop 2. But my question is that I have already mapreduce program which is written for hadoop 1 APIs. If i convert the code of hadoopAPI 1 to Hadoop API2 and run it on Hadoop2, will i get any performance improvement?