README
¶
Package weighted implements the smooth weighted round-robin balancing algorithm. This algorithm is implemented in Nginx: https://github.com/phusion/nginx/commit/27e94984486058d73157038f7950a0a36ecc6e35.
Algorithm is as follows: on each peer selection we increase current_weight of each eligible peer by its weight, select peer with greatest current_weight and reduce its current_weight by total number of weight points distributed among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of current_weight's: (a, a, b, a, c, a, a)
This is an example to use it:
package main
import "fmt"
func ExampleW1_Next() {
w := &W1{}
w.Add("a", 5)
w.Add("b", 2)
w.Add("c", 3)
for i := 0; i < 10; i++ {
fmt.Printf("%s ", w.Next())
}
}
And this lib has provides another weighted round robin algorithm. This algorithm is used in LVS. It has better performance but it is not so more smooth than the first algorithm, so you can select one algorithm according to your case. It is used like the first:
package main
import "fmt"
func ExampleW2_Next() {
w := &W2{}
w.Add("a", 5)
w.Add("b", 2)
w.Add("c", 3)
for i := 0; i < 10; i++ {
fmt.Printf("%s ", w.Next())
}
}
Documentation
¶
Overview ¶
Package weighted implements two weighted round robin algorithms. One is the smooth weighted round-robin balancing algorithm used in Nginx, and you can use "w := new W1{}" to use it. The other is wrr used in LVS and you can use "w := new W2{}" to use it.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type W ¶
type W interface {
Next() interface{}
Add(server interface{}, weight int)
RemoveAll()
Reset()
}
W is a interface that implement a weighted round robin algorithm.
type W1 ¶
type W1 struct {
// contains filtered or unexported fields
}
W1 is struct that contains weighted servers and provides methods to select a weighted server. It is used for the smooth weighted round-robin balancing algorithm. This algorithm is implemented in Nginx: https://github.com/phusion/nginx/commit/27e94984486058d73157038f7950a0a36ecc6e35.
Algorithm is as follows: on each peer selection we increase current_weight of each eligible peer by its weight, select peer with greatest current_weight and reduce its current_weight by total number of weight points distributed among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of current_weight's: (a, a, b, a, c, a, a)
func (*W1) Next ¶
func (w *W1) Next() interface{}
Next returns next selected server.
Example ¶
w := &W1{}
w.Add("a", 5)
w.Add("b", 2)
w.Add("c", 3)
for i := 0; i < 10; i++ {
fmt.Printf("%s ", w.Next())
}
Output: a c b a a c a b c a
func (*W1) NextWeighted ¶
NextWeighted returns next selected weighted object.
type W2 ¶
type W2 struct {
// contains filtered or unexported fields
}
W2 is struct that contains weighted servers implement LVS weighted round robin algorithm.
http://kb.linuxvirtualserver.org/wiki/Weighted_Round-Robin_Scheduling http://zh.linuxvirtualserver.org/node/37
Source Files