今天，我们在托管一个非常繁忙的网站的服务器上安装了 SSL 证书（来自letsencrypt）。
几个小时后，我们注意到我们有一些用户从 nginx 收到错误：
2018/03/28 13:04:48 [crit] 8997#8997: *604175694 SSL_do_handshake() failed (SSL: error:1417D18C:SSL routines:tls_process_client_hello:version too low) while SSL handshaking, client: 2.178.99.86, server: 0.0.0.0:443
2018/03/28 13:06:03 [crit] 9937#9937: *604177779 SSL_do_handshake() failed (SSL: error:1417D18C:SSL routines:tls_process_client_hello:version too low) while SSL handshaking, client: 5.73.106.149, server: 0.0.0.0:443
2018/03/28 13:06:46 [crit] 9949#9949: *604179134 SSL_do_handshake() failed (SSL: error:1417D18C:SSL routines:tls_process_client_hello:version too low) while SSL handshaking, client: 192.15.212.150, server: 0.0.0.0:443
2018/03/28 13:10:33 [crit] 9942#9942: *604185439 SSL_do_handshake() failed (SSL: error:1417D18C:SSL routines:tls_process_client_hello:version too low) while SSL handshaking, client: 5.234.36.205, …