ALFE: A Replacement Policy to Cache Elephant Flows in the Presence of Mice Flooding
Flow-based packet processing exists widely in a variety of network applications, where a large sized flow table is built to keep the alive flow records. To accelerate the search speed of the flow table, numerous systems employ cache mechanism to track the most recently referenced flows. However, network traffic exhibits some different characteristics from the workload of the general computational tasks, and classic replacement policies like LRU, Random, fail to perform well in the network scenarios. To develop a network-oriented flow cache replacement policy, the authors propose ALFE (Adaptive Least Frequently Evicted) based on the observations of traffic's heavy tailed feature and the statistically positive correlation between the flow size and the flow cache evict times.