Reducing the Latency-Tail of Short-Lived Flows: Adding Forward Error - PowerPoint PPT Presentation

ATP TCP Reducing the Latency-Tail of Short-Lived Flows: Adding Forward Error Correction in Data Centers Klaus-Tycho Foerster Demian Jaeger David Stolz Roger Wattenhofer ETH Zurich 1

Time is Money 2

Datacenter Traffic S. Kandula et al., The Nature of Datacenter Traffic. IMC 2009 Time in Datacenter 3

Overview Problem Prior Work   TCP is sensitive to Add forward error correction retransmissions (FEC) at link layer  Induces latency-tail in  Wireless networks congested networks  Add general overhead → Goal  Reserve capacity Our Approach  Adaptive FEC on packet level 1 2 3 1,2,3 4

ATP: A Protocol with Error Correction 1 2 1,2 3 4 5 3,4,5 6 7 8 9 6,7,8,9 10 11 12 5

Results Evaluation 6

Testbed 7

TCP - Background Traffic 8

Tail Latency 9

Conclusion ATP Evaluation   Transport Layer Protocol for Fairness to TCP and other ATP Datacenters Streams   Improve Latency of Small Flows Similar to TCP in not by using variable FEC Congested Network  20 Times smaller Tail Latency compared to TCP in busy Network 1 2 3 1,2,3 10