EYWA: Elastic Load-Balancing and High-Availability Wired Virtual Network Architecture

TL;DR

EYWA is a scalable virtual network architecture designed for large data centers, offering high availability, efficient load balancing, and extensive layer-2 features for multi-tenant cloud environments.

Contribution

It introduces a distributed control and data plane architecture that overcomes scalability and availability limitations of conventional overlay networks in IaaS.

Findings

Supports up to 16 million tenants with isolated virtual LANs.

Provides per-tenant public network services without bottlenecks.

Enables a single large IP subnet per tenant with extended layer-2 semantics.

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.