Implementation of SLB for Public Cloud

The large-scale migration and deployment of services to public clouds pose new challenges to the reliability and elastic scalability of public clouds. Server Load Balancing (SLB), as a traffic distribution technology, can route network service requests to different backend servers based on predefined rules, thereby achieving high availability and elastic scaling of network services. Traditional network load balancing technologies typically include Layer 3, Layer 4, and Layer 7 load balancing techniques, deployed in physical networks using hardware load balancers or IP layer load balancing functions in routers and switches. However, due to the virtualization characteristics and tenant isolation requirements of public clouds, traditional load balancing techniques cannot be directly applied to public clouds. This paper addresses the high availability and elastic scaling issues for tenants' services in a distributed routing architecture in public clouds and introduces Network Function Virtualization (NFV) technology. It proposes an SLB implementation technique that combines Layer 3 and Layer 4 to provide robust support for large-scale service deployments in public clouds. Performance analysis and experimental results indicate that the SLB implementation proposed in this paper offers excellent latency performance and horizontal scalability, meeting the needs of large-scale public cloud services.