一致性hash充电利器.pdf

Consistent Hashing and Random Trees: Distributed Caching Protocols for Relieving Hot Spots on the World Wide Web David Karger
Eric Lehman
Tom Leighton
  Matthew Levine
Daniel Lewin
Rina Panigrahy
    it was originally configured to handle. In fact, a site may receive so many requests that it becomes “swamped,” which typically renders We describe a family of caching protocols for distrib-uted networks it unusable. Besides making the one site inaccessible, heavy traffic that can be used to decrease or eliminate the occurrence of hot spots destined to one location can congest the network near it, interfering in the network. Our protocols are particularly designed for use with with traffic at nearby sites. very large networks such as the Internet, where delays caused by As use of the Web has increased, so has the occurrence and hot spots can be severe, and where it is not feasible for every server impact of hot spots. Recent famous examples of hot spots on the to have complete information about the current state of the entire Web include the JPL site after the Shoemaker-Levy 9 comet struck network. The protocols are easy to implement using existing net- Jupiter, an IBM site during the Deep Blue-Kasparov chess tour- work protocols such as TCP/IP, and require very little overhead. nament, and several political sites on the night of the election. In The protocols work with local control, make efficient use