Seron: Smart Query Router for Multi-Primary Cloud-Native Databases with Shared Storage

Abstract

Cloud-native databases have become a major deployment paradigm for commercial applications and services in recent years. One of the most promising development trends in cloud-native databases is to support multi-primary architecture with shared storage layers. However, when different writer nodes simultaneously access overlapping data ranges, query conflicts naturally arise, potentially leading to a significant performance drop. Therefore, it is of great importance to design query routers that can smartly separate incoming workloads to mitigate inter-node conflicts, which is a problem not fully discussed in the existing literature. To address this issue, in this paper, we present Seron, a smart query routing system customized for multi-primary cloud-native databases with shared storage. The system aims to minimize conflicts by directing each query to an optimal compute node. To this end, Seron generates workload-aware logical routing rules at different granularities using a two-stage framework, actively detects and handles physical data collisions through judicious conflict modeling, and constantly adapts its routing policies to provide the best runtime performance. The system has been integrated into GaussDB and deployed in real-world scenarios. Extensive experiments verify the effectiveness and cost-efficiency of Seron, which achieves up to 61.7% execution time reduction compared to the best baseline.