故障：

[root@localhost ~]# git clone https://github.com/percona/percona-xtradb-cluster.git
 fatal: unable to access 'https://github.com/percona/percona-xtradb-cluster.git/': Peer reports incompatible or unsupported protocol version.

原因：nss curl libcurl 版本太旧

解决办法：

[root@localhost ~]# yum update -y nss curl libcurl