This paper surveys tools and techniques used in the Big-data and Big-data computing. The principles upon which Big-data and dataintensive computations work have been explored with some outlines provided by various researchers in the field. The paper starts with the traditionalcluster computing and further explores about the Hadoop system as a tool to solve Big-data issues. It also covers the significant growth in cloudcomputing towards hosting MapReduce to use for Data-intensive computations as one of the services available through clouds. It has brief coverageabout Microsoft Azure and Amazon clouds for MapReduce services to be provided through Internet.