open-consul/command/agent/util.go
2014-08-21 14:28:16 -07:00

58 lines
1.3 KiB
Go

package agent
import (
"math"
"math/rand"
"os/exec"
"runtime"
"time"
)
const (
// This scale factor means we will add a minute after we
// cross 128 nodes, another at 256, another at 512, etc.
// By 8192 nodes, we will scale up by a factor of 8
aeScaleThreshold = 128
)
// aeScale is used to scale the time interval at which anti-entropy
// take place. It is used to prevent saturation as the cluster size grows
func aeScale(interval time.Duration, n int) time.Duration {
// Don't scale until we cross the threshold
if n <= aeScaleThreshold {
return interval
}
multiplier := math.Ceil(math.Log2(float64(n))-math.Log2(aeScaleThreshold)) + 1.0
return time.Duration(multiplier) * interval
}
// Returns a random stagger interval between 0 and the duration
func randomStagger(intv time.Duration) time.Duration {
return time.Duration(uint64(rand.Int63()) % uint64(intv))
}
// strContains checks if a list contains a string
func strContains(l []string, s string) bool {
for _, v := range l {
if v == s {
return true
}
}
return false
}
// ExecScript returns a command to execute a script
func ExecScript(script string) (*exec.Cmd, error) {
var shell, flag string
if runtime.GOOS == "windows" {
shell = "cmd"
flag = "/C"
} else {
shell = "/bin/sh"
flag = "-c"
}
cmd := exec.Command(shell, flag, script)
return cmd, nil
}