Review of "Fastpass: A Centralized “Zero-Queue” Datacenter Network"

18 Nov 2015

Review of "Fastpass: A Centralized “Zero-Queue” Datacenter Network"

This paper claims that an ideal DC network should provide several properties: 1) packets experience no queuing delays, 2) network has high throughput, 3) network should be able to support multiple resource allocation objectives between flows, applications and users. DC that doesn't have these properties makes it very hard to meet complex service-level objectives and application specific goals.

Key points and trade-offs: Traditional networking protocols are essentially a distributed protocols, congestion control is done at the end-points whereas path selections are done in the middle at switches. In this paper, the authors propose a centralized protocol to handle congestion and path selection. Which they call arbiter. With a centralized arbiter, they loose the scalability and fault-tolerance of the traditional approach but gained several key features such as consistently low latency, no persistent congestion and packets will never be dropped due to buffer overflow.

Will this paper be influential in 10 years? Yes, I think so. Traditional networking protocols are designed for the Internet, which can span across continents. But for networking inside a data center, many of the designs don't actually fit. This paper identifying that and proposing a centralized version – which is possible because it's networking within a data center – made a good option for considering the networking technology for building a better data center network.