On Black-Box Monitoring Techniques for Multi-Component Services

Despite the advantages of microservice and function-oriented architectures, there is an increase in complexity to monitor such highly dynamic systems. In this paper, we analyze two distinct methods to tackle the monitoring problem in a system with reduced instrumentation. Our goal is to understand the feasibility of such approach with one specific driver: simplicity. We aim to determine the extent to which it is possible to characterize the state of two generic tandem processes, using as little information as possible. To answer this question, we resorted to a simulation approach. Using a queue system, we simulated two services, that we could manipulate with distinct operation sets for each module. We used the total response time seen upstream of the system. Having this setup and metric, we applied two distinct methods to analyze the results. First, we used supervised machine learning algorithms to identify where the bottleneck is happening. Secondly, we used an exponential decomposition to identify the occupation in the two components in a more black-box fashion. Results show that both methodologies have their advantages and limitations. The separation of the signal more accurately identifies occupation in low occupied resources, but when a service is totally dominating the overall time, it lacks precision. The machine learning has a more stable error, but needs the training set. This study suggest that a black-box occupation approach with both techniques is possible and very useful.