Abstract: K-nearest neighbors (K-NN) is a lazy learning algorithm.It is unnecessary to train classification models,when one uses K-NN for data classification.K-NN algorithm is simple and easy to implement.The disadvantages of K-NN is that it requires large number of computations,which is introduced by calculating distances between testing instance and every training instance.Condensed nearest neighbors (CNN) can overcome the drawback of K-NN mentioned above.However,CNN is an iterative algorithm,when it is applied in big data scenario,its efficiency becomes very low.In order to deal with this problem,this paper proposed an algorithm named Spark CNN.In big data circumstances,Spark CNN can significantly improve the efficiency of CNN.This paper experimentally compared the Spark CNN with MapReduce CNN on 5 big data sets,the experimental results show that the Spark CNN is very effective.

Key words: Big data, Condensed nearest neighbors, Instance selection, Iterative calculation, Lazy learning