(Round-Robin Scheduling) principle robin scheduling algorithm is in turn assigned to each request from the user to the server in the internal, from the beginning, until N (the number of internal servers), and then begin the cycle anew.
Advantages: simple, without recording all of the current state of the connection, so it is a stateless scheduling.
Disadvantages: Due to the algorithm does not care about the current number of connections and the response speed of each server, when the requested service interval time is relatively large, round robin scheduling algorithm easily lead to unbalanced load between servers