A Mathematical Framework for the Detection of Elephant Flows
Jordi Ros-Giralt, Alan Commike, Sourav Maji, Malathi Veeraraghavan
Publication Source: Extended Mathematical Report
How large is a network flow? Traditionally this question has been addressed by using metrics such as the number of bytes, the transmission rate or the duration of a flow. We reason that a formal mathematical definition of flow size should account for the impact a flow has on the performance of a network: flows that have the largest impact, should have the largest size. In this paper we present a theory of flow ordering that reveals the connection between the abstract concept of flow size and the QoS properties of a network. The theory is generalized to accommodate for the case of partial information, allowing us to model real computer network scenarios such as those found in involuntary lossy environments or voluntary packet sampling protocols (e.g., sFlow). We explore one application of this theory to address the problem of elephant flow detection at very high speed rates. The algorithm uses the information theoretic properties of the problem to help reduce the computational cost by a factor of one thousand.