Scheduling traffic for maximum switch lifetime in optical data center fabrics

Optical switching is a promising technology to scale the performance of data centers. We address two scenarios: hybrid data centers, in which an optical circuit switching network operates in parallel to an electronic packet switching network that interconnect the servers, and full optical data centers, in which all the traffic is switched in the optical domain. The traffic on the optical network is scheduled proactively by configuring the optical fabric according to a precomputed sequence of configurations. We consider that fast optical circuit switching is implemented through micro-mechanical devices (like MEMS) at each crosspoint, whose lifetime is limited by a maximum number of configuration cycles, due to the experienced mechanical fatigue. We consider the traffic scheduling problem on the optical network and address specifically the problem of minimizing the number of reconfigurations at each crosspoint, in order to maximize the MEMS lifetime, while maximizing the throughput. We propose a family of scheduling algorithms and discuss the achievable tradeoff between lifetime, throughput and computational complexity, throughout a set of extensive simulations and theoretical results.