  Numerous optical circuit switched data center networks have been proposed
over the past decade for higher capacity, though commercial adoption of these
architectures have been minimal so far. One major challenge commonly facing
these architectures is the difficulty of handling bursty traffic with optical
circuit switches (OCS) with high switching latency. Prior works generally rely
on fast-switching OCS prototypes to better react to traffic changes via
frequent reconfigurations. This approach, unfortunately, adds further
complexity to the control plane. We propose METTEOR, an easily deployable
solution for optical circuit switched data centers, that is designed for the
current capabilities of commercial OCSs. Using multiple predicted traffic
matrices, METTEOR designs data center topologies that are less sensitive to
traffic changes, thus eliminating the need of frequently reconfiguring OCSs
upon traffic changes. Results based on extensive evaluations using production
traces show that METTEOR increases the percentage of direct-hop traffic by
about 80% over a fat tree at comparable cost, and by about 30% over a uniform
mesh, at comparable maximum link utilizations. Compared to ideal solutions that
reconfigure OCSs on every traffic matrix, METTEOR achieves close-to-optimal
bandwidth utilization even with biweekly reconfiguration. This drastically
lowers the controller and management complexity needed to perform METTEOR in
commercial settings.

Networking and Internet Architecture