// Listen UDP packet and write to channel
func (this *Watcher) listen() (chan string, error) {
lis, err := net.ListenPacket("udp", this.Addr)
if err != nil {
return nil, err
}
beelog.Info("start listen packet from", this.Addr)
ch := make(chan string)
go func() {
defer lis.Close()
buf := make([]byte, 1000)
for {
n, addr, err := lis.ReadFrom(buf)
msg := string(buf[:n])
beelog.Debug("Receive from", addr, msg)
if err != nil {
beelog.Warn(err)
continue
}
ip := strings.Split(addr.String(), ":")[0]
ch <- ip
}
}()
return ch, nil
}
// auto decrease host HP
func (this *Watcher) drain(notify chan Host) {
beelog.Debug("drain stated")
for {
this.Lock()
for _, host := range this.Hosts {
var state = host.Alive
this.hurt(host.IP)
beelog.Debug("drain", host.IP, host.HP, host.Alive)
if host.Alive != state {
notify <- *host
}
}
this.Unlock()
time.Sleep(this.RecycleDuration)
}
}
// tell the master I'am alive
func Beat(addr string, msg string) {
conn, err := net.DialTimeout("udp", addr, time.Second*2)
if err != nil {
beelog.Error(err)
return
}
defer conn.Close()
beelog.Debug("beat send msg:", msg)
_, err = conn.Write([]byte(msg))
return
}