Auto-scaling techniques for elastic data stream processing

An elastic data stream processing system is able to handle changes in workload by dynamically scaling out and scaling in. This allows for handling of unexpected load spikes without the need for constant overprovisioning. One of the major challenges for an elastic system is to find the right point in time to scale in or to scale out. Finding such a point is difficult as it depends on constantly changing workload and system characteristics. In this paper we investigate the application of different auto-scaling techniques for solving this problem. Specifically: (1) we formulate basic requirements for an auto-scaling technique used in an elastic data stream processing system (2) we use the formulated requirements to select the best auto scaling techniques and (3) we perform evaluation of the selected auto scaling techniques using the real world data. Our experiments show that the auto scaling techniques used in existing elastic data stream processing systems are performing worse than the strategies used in our work.