🤖 AI Summary
This work addresses the scalability bottlenecks and the inherent trade-off between high availability and load balancing in traditional cloud IaaS virtual networks under multi-tenant environments. To overcome these limitations, the authors propose a fully distributed virtual network architecture that eliminates centralized control and data planes by leveraging per-host agents. The design supports VLAN-based isolation for up to approximately 16.7 million tenants, accommodates large IP subnets per tenant, and provides SNAT/DNAT services without throughput bottlenecks—all while preserving large Layer 2 semantics and eliminating single points of failure. Prototype evaluation demonstrates that the proposed architecture achieves high availability, efficient load balancing, and elastic scalability to large-scale deployments, significantly enhancing the performance and reliability of multi-tenant virtual networks.
📝 Abstract
Infrastructure as a Service (IaaS) in cloud environments provides compute, storage, networking, and other fundamental resources that allow consumers to deploy and run arbitrary software, including operating systems and applications. To support multi-tenant environments, IaaS leverages virtualization, but conventional overlay network architectures have become a direct cause of scalability limitations. In particular, current IaaS virtual networks face challenges in high availability and load balancing. To address these issues, we present EYWA, a virtual network architecture that scales to support very large data centers with high availability, efficient load balancing, and large layer-2 semantics. EYWA overcomes scalability limitations by: (1) accommodating a large number of tenants (about 2^24 = 16,777,216) through logically isolated virtual LANs with unique IP ranges, (2) providing per-tenant public network services without throughput bottlenecks or single points of failure in network address translation (SNAT/DNAT), and (3) enabling a single large IP subnet per tenant with extended layer-2 semantics. EYWA combines existing techniques into a distributed scale-out control and data plane. Its only component is an agent running on each hypervisor host, which collectively act as a distributed controller. As a result, EYWA can be deployed in today's multi-tenant cloud environments. We have implemented a proof-of-concept (PoC) of EYWA and evaluated its effectiveness through measurements and experiments in our lab.