Myths and Realities of MR
Tuesday, February 22, 2011
12:26 PM
Myths and Realities of MR
Google MR is fast because
Map and Reduce are pre-coded. 
There is no need to propogate code. 
Hadoop MR has a very slow startup time because
Must propogate jarfile for Map, Combine, Reduce classes to each Hadoop node. 
Up to 30 seconds for a large array. 
So, basically no one uses it for real time queries. 