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：

-- ::, [myid:] - INFO  [WorkerSender[myid=]:QuorumPeer$QuorumServer@] - Resolved hostname: 192.168.52.27 to address: /192.168.52.27
-- ::, [myid:] - INFO  [WorkerReceiver[myid=]:FastLeaderElection@] - Notification:  (message format version),  (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state),  (n.sid), 0x6 (n.peerEpoch) LOOKING (my state)
-- ::, [myid:] - WARN  [WorkerSender[myid=]:QuorumCnxManager@] - Cannot open channel to  at election address /192.168.52.27:
java.net.ConnectException: 拒绝连接 (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:)
    at java.net.Socket.connect(Socket.java:)
    at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:)
    at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:)
    at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:)
    at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:)
    at java.lang.Thread.run(Thread.java:)
-- ::, [myid:] - INFO  [WorkerSender[myid=]:QuorumPeer$QuorumServer@] - Resolved hostname: 192.168.52.27 to address: /192.168.52.27
-- ::, [myid:] - INFO  [/192.168.52.28::QuorumCnxManager$Listener@] - Received connection request /192.168.52.27:
-- ::, [myid:] - INFO  [WorkerReceiver[myid=]:FastLeaderElection@] - Notification:  (message format version),  (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state),  (n.sid), 0x6 (n.peerEpoch) LOOKING (my state)
-- ::, [myid:] - INFO  [WorkerReceiver[myid=]:FastLeaderElection@] - Notification:  (message format version),  (n.leader), 0x1000000b2 (n.zxid), 0x1 (n.round), LOOKING (n.state),  (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。