启动cqlsh时，保存如下：
Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
在启动时，指定连接的IP和端口
./cqlsh xxx.xxx.xxx.xxx 9042
输出结果如下：
Connected to Test Cluster at 100.106.242.180:9042. [cqlsh 5.0.1 | Cassandra 3.9 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help. cqlsh>