How can we analyze very large real-world tensors where additional information is coupled with certain modes of tensors? Coupled matrix-tensor factorization is a useful tool to simultaneously analyze matrices and a tensor, and has been used for important applications including collaborative filtering, multi-way clustering, and link prediction. However, existing single machine or distributed algorithms for coupled matrix-tensor factorization do not scale for tensors with billions of elements in each mode. In this paper, we propose SCOUT, a large-scale coupled matrix-tensor factorization algorithm running on the distributed MAPREDUCE platform. By carefully reorganizing operations, and reusing intermediate data, SCOUT decomposes up to 100× larger tensors than existing methods, and shows linear scalability for order and machines while other methods are limited in scalability. We also apply SCOUT on real world tensors and discover interesting hidden patterns like seasonal spike, and steady attentions for healthy food on Yelp dataset containing user-business-yearmonth tensor and two coupled matrices.

How can we find useful patterns and anomalies in large scale real-world data with multiple attributes? For example, network intrusion logs, with (source-ip, target-ip, port-number, timestamp)? Tensors are suitable for modeling these multi-dimensional data, and widely used for the analysis of social networks, web data, network traffic, and in many other settings. However, current tensor decomposition methods do not scale for tensors with millions and billions of rows, columns and `fibers', that often appear in real datasets. In this paper, we propose HaTen2, a scalable distributed suite of tensor decomposition algorithms running on the MapReduce platform. By carefully reordering the operations, and exploiting the sparsity of real world tensors, HaTen2 dramatically reduces the intermediate data, and the number of jobs. As a result, using HaTen2, we analyze big real-world tensors that can not be handled by the current state of the art, and discover hidden concepts.