func New(servicename, serviceport string) (*Ring, error) {
// XXX 在Mac上调试时，Mac没有eth0接口，会导致ring.New()失败。
// 建议增加一个参数，允许用户传入指定的Interface（因此用户程序可以将该配置写入配置文件）。
// 目前考虑到API兼容性，在上述方法获得一致同意前，不改动API，而是从环境变量读取。
iface, ok := os.LookupEnv("RING_SERVER_INTERFACE")
if !ok {
iface = "eth0"
}
localIp, err := externalIP(iface)
if err != nil {
return nil, err
}
mc, err := cache.NewCache("memory", `{"interval":60}`)
if err != nil {
return nil, err
}
serverId := localIp + ":" + serviceport + ":" + strconv.Itoa(os.Getpid()) + ":" + strconv.FormatInt(startTime, 10)
r := Ring{
selfServerId: serverId,
servicename: servicename,
hashring: hashring.New([]string{serverId}),
stop: make(chan struct{}),
cache: mc,
}
r.register()
r.subscribe()
return &r, nil
}
func (this *Ring) refreshHashring() {
var serverIds []string
serverIds = append(serverIds, this.selfServerId)
hs, err := service.Get(this.servicename)
for err != nil {
errEtcd := err.(*etcd.EtcdError)
logger.Println("Lost etcd registrationg for", this.servicename, ":", errEtcd.ErrorCode)
time.Sleep(1 * time.Second)
hs, err = service.Get(this.servicename)
if err == nil {
logger.Println("Recover etcd connection for", this.servicename)
}
}
for idx, h := range hs {
logger.Printf("No.%v host %v\n", idx, h.Name)
serverIds = append(serverIds, h.Name)
}
this.Lock()
defer this.Unlock()
this.hashring = hashring.New(serverIds)
this.cache.ClearAll()
}