A hybrid network architecture for modular data centers
- Author(s): Radhakrishnan, Sivasankar
- et al.
The emergence of the mega data center has resulted in the basic building block of ever larger data centers changing from a rack comprising tens of servers to a self-contained modular shipping container that holds upto a thousand servers. These self-contained modular blocks include networking, power and cooling equipment besides servers. However, provisioning bandwidth between these containers at a large scale is still a significant challenge. Traditional approaches to provisioning bandwidth use electrical packet switches with a scale-up architecture and are often highly oversubscribed. More recent proposals such as those using clos networks promise full bisection bandwidth between servers, albeit at a high cost and power consumption. We present Helios, a hybrid architecture for modular data centers that combines electrical packet switching and optical circuit switching in a single network and dynamically provisions bandwidth between the modular containers on demand. We investigate this design from an architectural standpoint by building a fully functional prototype and explore its implications for data center networks and the challenges that it introduces. Our prototype shows the feasibility of building such a system and achieving high performance at considerably lower cost. Additionally it uncovers several issues that pose new challenges for designing large data center networks and problems that arise when circuits are rapidly reconfigured