Challenges in service discovery for microservices deployed in a Kubernetes cluster - a case study

With Kubernetes emerging as one of the most popular infrastructures in the cloud-native era, the utilization of containerization and tools alongside Kubernetes is steadily gaining traction. The main goal of this paper is to evaluate the service discovery mechanisms and DNS management (CoreDNS) of Kubernetes, and to present a general study of an experiment on service discovery challenges. In large scale Kubernetes clusters, running pods, services, requests, and workloads can be substantial. The increased number of HTTP-requests often result in resource utilization concerns, e.g., spikes of errors [24], [25]. This paper investigates potential optimization strategies for enhancing the performance and scalability of CoreDNS in Kubernetes. We propose a solution to address the concerns related to CoreDNS and provide a detailed explanation of how our implementation enhances service discovery functionality. Experimental results in a real-world case show that our solution for the CoreDNS ensures consistency of the workload. Compared with the default CoreDNS configuration, our customized approach achieves better performance in terms of number of errors for requests, average latency of DNS requests, and resource usage rate.