VirtualRack: Bandwidth-Aware Virtual Network Allocation for Multi-Tenant Datacenters

It has become a common practice that enterprises outsource their networks to the cloud by renting multiple virtual machines (VMs) in cloud datacenters. Due to the multi-tenant nature of cloud datacenter, how to efficiently share the network resources becomes an important issue. Recent studies, e.g., SecondNet and Oktopus, have taken network bandwidth into consideration when allocating VMs. However, these schemes are problematic in that the allocation is not that accurate, and can result in a low multiplexing rate. To this end, we present VirtualRack (VR), a new bandwidth-aware VM allocation scheme in multi-tenant datacenters. VR simultaneously considers intra-datacenter bandwidth and Internet-access-bandwidth requirements in the allocation process. In addition, we introduce a redundancy factor a that can be specified by tenants to accommodate their dynamic requirements. Simulation results show that VR can guarantee the network performance for each of the multiple tenants, and at the same time keep a high acceptance ratio without any false allocation.