Google MapReduce读后感

一、Introduction
MapReduce is a programming model and it is abstraction that allows us to express the simple computations
we were trying to perform but hides the messy details of parallelization,fault-tolerance,data distribution and load balancing.
MapReduce is just concept and interface.


二、Programming Model
how to use Google Implementaion of MapReduce?
write your own map function and reduce function,the others can be done by invocating the API of Google Implementaion Of MapReduce


三、Implementation
Many different implementation of the MapReduct interface are possible.
the right choice depends on the environment.
For example, one implementation may be suitable for a small shared-memory machine, another for a large NUMA multi-processor, and yet another for an even larger collection of networked machines.
Google has two implementation,one is GFS which is the impletation of distributed file system interface and the other is the implementation of MapReduce interface