异常：
1 java.net.ConnectException: Connection timed out: no further information 2 at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) 3 at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) 4 at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361) 5 at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1141) 6 2020-06-05 10:44:12,901 [localhost-startStop-1-SendThread(192.168.202.128:2181)] [org.apache.zookeeper.ClientCnxnSocketNIO]-[DEBUG] Ignoring exception during shutdown input 7 java.nio.channels.ClosedChannelException 8 at sun.nio.ch.SocketChannelImpl.shutdownInput(SocketChannelImpl.java:780) 9 at sun.nio.ch.SocketAdaptor.shutdownInput(SocketAdaptor.java:399) 10 at org.apache.zookeeper.ClientCnxnSocketNIO.cleanup(ClientCnxnSocketNIO.java:200) 11 at org.apache.zookeeper.ClientCnxn$SendThread.cleanup(ClientCnxn.java:1246) 12 at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1170) 13 2020-06-05 10:44:12,902 [localhost-startStop-1-SendThread(192.168.202.128:2181)] [org.apache.zookeeper.ClientCnxnSocketNIO]-[DEBUG] Ignoring exception during shutdown output 14 java.nio.channels.ClosedChannelException 15 at sun.nio.ch.SocketChannelImpl.shutdownOutput(SocketChannelImpl.java:797) 16 at sun.nio.ch.SocketAdaptor.shutdownOutput(SocketAdaptor.java:407) 17 at org.apache.zookeeper.ClientCnxnSocketNIO.cleanup(ClientCnxnSocketNIO.java:207) 18 at org.apache.zookeeper.ClientCnxn$SendThread.cleanup(ClientCnxn.java:1246) 19 at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1170)
解决：关闭服务端防火墙，service iptables stop这条命令无效，要使用：systemctl stop firewalld.service