Machine learning-based auto-scaling for containerized applications

Containers are shaping the new era of cloud applications due to their key benefits such as lightweight, very quick to launch, consuming minimum resources to run an application which reduces cost, and can be easily and rapidly scaled up/down as per workload requirements. However, container-based cloud applications require sophisticated auto-scaling methods that automatically and in a timely manner provision and de-provision cloud resources without human intervention in response to dynamic fluctuations in workload. To address this challenge, in this paper, we propose a proactive machine learning-based approach to perform auto-scaling of Docker containers in response to dynamic workload changes at runtime. The proposed auto-scaler architecture follows the commonly abstracted four steps: monitor, analyze, plan, and execute the control loop. The monitor component continuously collects different types of data (HTTP request statistics, CPU, and memory utilization) that are needed during the analysis and planning phase to determine proper scaling actions. We employ in analysis phase a concise yet fast, adaptive, and accurate prediction model based on long short-term memory (LSTM) neural network to predict future HTTP workload to determine the number of containers needed to handle requests ahead of time to eliminate delays caused by starting or stopping running containers. Moreover, in the planning phase, the proposed gradually decreasing strategy avoids oscillations which happens when scaling operations are too frequent. Experimental results using realistic workload show that the prediction accuracy of LSTM model is as accurate as auto-regression integrated moving average model but offers 600 times prediction speedup. Moreover, as compared with artificial neural network model, LSTM model performs better in terms of auto-scaler metrics related to provisioning and elastic speedup. In addition, it was observed that when LSTM model is used, the predicted workload helped in using the minimum number of replicas to handle future workload. In the experiments, the use of GDS showed promising results in keeping the desired performance at reduced cost to handle cases with sudden workload increase/decrease.