报错：WARN [WorkerSender[myid=1]:QuorumCnxManager@584] - Cannot open channel to 2 at election address /x.x.x.x:3888

报错背景：

zookeeper安装完成之后，启动之后正常，但是查看log文件zookeeper.log时发现报错。

报错现象：

2019-05-22 11:40:38,469 [myid:1] - INFO  [WorkerSender[myid=1]:QuorumPeer$QuorumServer@185] - Resolved hostname: 192.168.52.27 to address: /192.168.52.27
2019-05-22 11:40:38,470 [myid:1] - INFO  [WorkerReceiver[myid=1]:FastLeaderElection@595] - Notification: 1 (message format version), 3 (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state), 1 (n.sid), 0x6 (n.peerEpoch) LOOKING (my state)
2019-05-22 11:40:38,470 [myid:1] - WARN  [WorkerSender[myid=1]:QuorumCnxManager@584] - Cannot open channel to 2 at election address /192.168.52.27:3888
java.net.ConnectException: 拒绝连接 (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:558)
    at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:534)
    at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:454)
    at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:435)
    at java.lang.Thread.run(Thread.java:748)
2019-05-22 11:40:38,470 [myid:1] - INFO  [WorkerSender[myid=1]:QuorumPeer$QuorumServer@185] - Resolved hostname: 192.168.52.27 to address: /192.168.52.27
2019-05-22 11:40:38,504 [myid:1] - INFO  [/192.168.52.28:3888:QuorumCnxManager$Listener@743] - Received connection request /192.168.52.27:56020
2019-05-22 11:40:38,508 [myid:1] - INFO  [WorkerReceiver[myid=1]:FastLeaderElection@595] - Notification: 1 (message format version), 2 (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state), 2 (n.sid), 0x6 (n.peerEpoch) LOOKING (my state)
2019-05-22 11:40:38,514 [myid:1] - INFO  [WorkerReceiver[myid=1]:FastLeaderElection@595] - Notification: 1 (message format version), 3 (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state), 2 (n.sid), 0x6 (n.peerEpoch) LOOKING (my state)

报错原因：

如果是刚启动zookeeper报出这个错误，然后不再不错，那就是正常现象。是由于有的节点启动，而有的节点还没有启动，这段时间已经启动的节点就会去努力寻找没有启动的节点，就会报出这样的错误。这是一种正常现象，无需多虑。

如果启动很长时间之后还在报错，可以尝试下面的饿解决方案。

报错解决：

修改每个节点的zoo.cfg文件中的相对应的server.x=0.0.0.0:2888:3888

修改完成后重启zookeeper，报错消失。