Providing Reliable Service in Data-center Networks

Transport Control Protocol (TCP) in cast congestion happens in high-bandwidth and low-latency networks when multiple synchronized servers send data to the same receiver in parallel. For many important data-center applications such as Map Reduce and Search, this many-to- one traffic pattern is common. Hence TCP in cast congestion may severely degrade their performances, e.g., by increasing response time. In this paper, we study TCP in cast in detail by focusing on the relationships between TCP throughputs, round-trip time (RTT), and receive window. Unlike previous approaches, which mitigate the impact of TCP in cast congestion by using a fine- grained timeout value, our idea is to design an In cast congestion Control for TCP (ICTCP) scheme on the receiver side. In particular, our method adjusts the TCP receive window proactively before packet loss occurs. The implementation and experiments in our test bed demonstrate that we achieve almost zero timeouts and high good put for TCP in cast. Hence, TCP connections with short round-trip times may receive unfairly large allocations of network bandwidth when compared to connections with longer round-trip times.