Eat all keep alive messages

When use etcd keepalive method, we must consume all messages
from the queen it retured.Otherwise, the queen would be full.
See more detail, visit the follow links:

etcd-io/etcd#9952
etcd-io/etcd#8168
https://github.com/coreos/etcd/blob/master/clientv3/concurrency/session.go#L63
https://www.cnxct.com/etcd-lease-keepalive-debug-note/

registry/etcdv3/register.go

@@ -115,12 +115,27 @@ func Register(ndata string) error {
 	// we must use context without timeout. Otherwise, the
 	// grpclient cannot receive any response from grpcserver after
 	// timeout.
-	if _, err = client.KeepAlive(context.TODO(), resp.ID); err != nil {
+	keep, err := client.KeepAlive(context.TODO(), resp.ID)
+	if nil != err {
 		logging.LOG.Errorf(
 			"Failed refresh the key %s exsit in etcd:%v\n",
 			key, err)
 		return err
 	}
+
+	// Eat all keep alive messages
+	// Otherwise, lease keepalive response queue will full,
+	// and etcd would dropping response send
+	// For more detail, visit the follow links:
+	// https://github.com/coreos/etcd/pull/9952
+	// https://github.com/coreos/etcd/issues/8168
+	// https://github.com/coreos/etcd/blob/master/clientv3/concurrency/session.go#L63
+	// https://www.cnxct.com/etcd-lease-keepalive-debug-note/
+
+	go func() {
+		for range keep {
+		}
+	}()
 	return nil
 }