The Kaiju project: enabling event-driven observability

Microservices architectures are getting momentum. Even small and medium-size companies are migrating towards cloud-based distributed solutions supported by lightweight virtualization techniques, containers, and orchestration systems. In this context, understanding the system behavior at runtime is critical to promptly react to errors. Unfortunately, traditional monitoring techniques are not adequate for such complex and dynamic environments. Therefore, a new challenge, namely observability, emerged from precise industrial needs: expose and make sense of the system behavior at runtime. In this paper, we investigate observability as a research problem. We discuss the benefits of events as a unified abstraction for metrics, logs, and trace data, and the advantages of employing event stream processing techniques and tools in this context. We show that an event-based approach enables understanding the system behavior in near real-time more effectively than state-of-the-art solutions in the field. We implement our model in the Kaiju system and we validate it against a realistic deployment supported by a software company.