Deadline and Incast Aware TCP for Data Center Networks

Nowadays, data centers have been a key resource to provide a plethora of rich online services such as web search and social networking. The data center applications follow the Partition/Aggregate traffic pattern based on a tree-like logical topology, where the aggregator node may gather response data from thousands of worker nodes. One of the key challenges for such applications, however, is to meet the soft real-time constraints. In this paper, we introduce the design and implementation of DIATCP, a new transport protocol that is both deadline-aware and incast-avoidable for data center applications. Prior work achieve deadline awareness by host-based or network-based approaches, but they are either imperfect in meeting their deadlines or have weakness in practical deployment, respectively. In contrast, DIATCP is deployed only at the aggregator, which directly controls the peers' sending rate to avoid incast congestion and, more importantly, to meet the application deadline. This is under the key observation that the aggregator knows the bottleneck link status as well as its workers' information under the Partition/Aggregate traffic pattern. Through detailed ns-3 simulations and real testbed experiments, we show that DIATCP significantly improves in terms of both deadline awareness and incast avoidance.