Pattern of a MapReduce function
Tuesday, February 23, 2010
6:10 PM
Pattern of a MapReduce algorithm
Distribute data to be operated upon on mappers. 
Distribute query data  (arguments to Map) to all mappers.  Sometimes called "scattering". 
Map: do the query. 
Reduce: collect and summarize results of the query. Sometimes called "gathering".  
(An old name for MapReduce: Scatter/Gather)