Inside the Social Network's (Datacenter) Network

Arjun Roy, Hongyi Zeng, Jasmeet Bagga, George Porter, Alex C. Snoeren
2015 Computer communication review  
Large cloud service providers have invested in increasingly larger datacenters to house the computing infrastructure required to support their services. Accordingly, researchers and industry practitioners alike have focused a great deal of effort designing network fabrics to efficiently interconnect and manage the traffic within these datacenters in performant yet efficient fashions. Unfortunately, datacenter operators are generally reticent to share the actual requirements of their
more » ... , making it challenging to evaluate the practicality of any particular design. Moreover, the limited large-scale workload information available in the literature has, for better or worse, heretofore largely been provided by a single datacenter operator whose use cases may not be widespread. In this work, we report upon the network traffic observed in some of Facebook's datacenters. While Facebook operates a number of traditional datacenter services like Hadoop, its core Web service and supporting cache infrastructure exhibit a number of behaviors that contrast with those reported in the literature. We report on the contrasting locality, stability, and predictability of network traffic in Facebook's datacenters, and comment on their implications for network architecture, traffic engineering, and switch design. Finding Previously published data Potential impacts Traffic is neither rack local nor all-to-all; low utilization ( §4) 50-80% of traffic is rack local [12, 17] Datacenter fabrics [4, 36, 21] Demand is wide-spread, uniform, and stable, with rapidly changing, internally bursty heavy hitters ( §5) Demand is frequently concentrated and bursty [12, 13, 14] Traffic engineering [5, 14, 25, 39] Small packets (outside of Hadoop), continuous arrivals; many concurrent flows ( §6) Bimodal ACK/MTU packet size, on/off behavior [12] ; <5 concurrent large flows [8] SDN controllers [1, 22, 28, 32, 34] ; Circuit/hybrid switching [7, 20, 30, 39]
doi:10.1145/2829988.2787472 fatcat:nbrnx5qj3ng6fipaoipmnj6rh4