Load Balancing Based on Consistent Hashing in P4 Switches

ABSTRACT In recent years, the emergence of new network architectures has seen substantial growth. Among these advancements, distributed server architectures and server load balancing have gradually become key areas of focus. This paper introduces a mechanism called consistent hashing with congestion awareness (CHCA), designed to optimize load balancing. CHCA enhances traditional algorithms by minimizing data migration when servers are added or removed. Additionally, this mechanism incorporates the least connections method to prevent certain servers from becoming overloaded due to persistent traffic, thereby mitigating server hotspots. Aiming to support this mechanism, two custom headers, the forward header and the MRI header, are introduced using P4 switches. The forward header allows P4 switches to make dynamic packet forwarding decisions based on optimal paths at runtime, eliminating the need for a static routing table. Meanwhile, the MRI header records the load information from all traversed P4 switches, enabling the load balancing forwarding strategy to adapt in real time based on current network conditions.