This may beof some use, about how maps are decided: http://wiki.apache.org/hadoop/HowManyMapsAndReduces
Thanks Hemanth On Friday, January 25, 2013, jamal sasha wrote: > Hi. > A very very lame question. > Does numbers of mapper depends on the number of nodes I have? > How I imagine map-reduce is this. > For example in word count example > I have bunch of slave nodes. > The documents are distributed across these slave nodes. > Now depending on how big the data is, it will spread across the slave > nodes.. and that is how my number of mappers are decided. > I am sure, this is wrong understanding. As in pseudo-distributed node, i > can see multiple mappers. > So question is.. how does a single node machine runs multiple mappers? is > it run in parallel or sequentially?? > Any resources to learn these > Thanks >