Chatty Tenants and the Cloud Network Sharing Problem
The emerging ecosystem of cloud applications leads to significant inter-tenant communication across a datacenter's internal network. This poses new challenges for cloud network sharing. Richer inter-tenant traffic patterns make it hard to offer minimum bandwidth guarantees to tenants. Further, for communication between economically distinct entities, it is not clear whose payment should dictate the network allocation. Motivated by this, the authors study how a cloud network that carries both intra- and inter-tenant traffic should be shared. They argue for network allocations to be dictated by the least-paying of communication partners. This, when combined with careful VM placement, achieves the complementary goals of providing tenants with minimum bandwidth guarantees while bounding their maximum network impact.