Using machine learning to optimize parallelism in big data applications

In-memory cluster computing platforms have gained momentum in the last years, due to their ability to analyse big amounts of data in parallel. These platforms are complex and difficult-to-manage environments. In addition, there is a lack of tools to better understand and optimize such platforms that consequently form the backbone of big data infrastructure and technologies. This directly leads to underutilization of available resources and application failures in such environment. One of the key aspects that can address this problem is optimization of the task parallelism of application in such environments. In this paper, we propose a machine learning based method that recommends optimal parameters for task parallelization in big data workloads. By monitoring and gathering metrics at system and application level, we are able to find statistical correlations that allow us to characterize and predict the effect of different parallelism settings on performance. These predictions are used to recommend an optimal configuration to users before launching their workloads in the cluster, avoiding possible failures, performance degradation and wastage of resources. We evaluate our method with a benchmark of 15 Spark applications on the Grid5000 testbed. We observe up to a 51% gain on performance when using the recommended parallelism settings. The model is also interpretable and can give insights to the user into how different metrics and parameters affect the performance.