A libray for weighted balancing algorithm.
It provides three weighted balancing (elect) algorithm.
One is random algorithm.
Another is weighted balancing algorithm used by LVS.
The third is smooth weighted balancing algorithm used by Nginx.
The LVS weighted round-robin scheduling is introduced at http://kb.linuxvirtualserver.org/wiki/Weighted_Round-Robin_Scheduling.
The Nginx smooth weighted round-robin balancing algorithm is introduced at https://github.com/phusion/nginx/commit/27e94984486058d73157038f7950a0a36ecc6e35.
The random algorithm is not smooth although it follows weight configuration.
Using it is simple:
use weighted_rs::{SmoothWeight, Weight};
use std::collections::HashMap;
let mut sw: SmoothWeight<&str> = SmoothWeight::new();
sw.add("server1", 5);
sw.add("server2", 2);
sw.add("server3", 3);
let mut results: HashMap<&str, usize> = HashMap::new();
for _ in 0..100 {
let s = sw.next().unwrap();
println!("{}", s);
}